. Known for tumor-suppression transcriptional regulation activities, the Retinoblastoma (Rb or Rbf in flies) protein plays a crucial role in cell-cycle regulation and apoptosis. More recently, an established a cytosolic role and mitochondrial localization, the Rb protein seems to cooperate with Drp1 to regulate mitochondrial quality in a transcriptionindependent manner. Control of mitochondrial quality is vital for the assurance of cell survival, and the failure of this function may result in catastrophic mitochondrial dysfunction and cell death. Here we exploited the UAS-Gal4 expression system to direct expression in neurons via the Ddc-Gal4 directing transgene. The directed expression of Drp1 in neuronal populations that include the dopaminergic (DA) neurons under the control of the Ddc-Gal4 transgene can produce a robust Drosophila model of Parkinson Disease (PD) with a severely reduced median lifespan and premature locomotor dysfunction. These are significantly suppressed when Rbf is also overexpressed. Intriguingly, the co-expression of Drp1-RNAi and Rbf-RNAi can restore aging defects associated with Rbf loss of function. A delicate balance between Rbf and Drp activities, to benefit the health of the mitochondrial network, seems to be essential during aging.

Mitochondrial health depends upon proteins that counteract dysfunction generated by cellular stress due to impairment of essential cellular pathways. The expression of the Bcl-2 family genes, the E3 ubiquitin ligase encoding, parkin, and the transcription regulator gene, Rbf/Rb, play significant roles in mitochondrial and cellular survival. Under conditions of extreme cellular stress, mitochondria can act to promote apoptosis. The overexpression of Rbf in the dopaminergic neurons of Drosophila directed by Ddc-Gal4 can result in flies with a reduced median lifespan and impaired climbing ability over time: a well-established Drosophila model of Parkinson Disease (PD). The inhibition of Rbf can lead to a premature reduction in locomotor ability compared to control. The overexpression of Rbf can rescue the neurodegenerative phenotypes induced due to the loss of function of parkin. The expression of the pro-cell survival Bcl-2 family member Buffy and inhibition of the anti-apoptotic Debcl can rescue the longevity and impaired locomotor ability over time observed in a model of PD induced by Rbf-RNAi. Overall, the alteration of expression of Rbf in selected neurons can produce a novel model of PD in Drosophila; the directed expression of Buffy acts to protect to counteract the Rbf-RNAi- induced deficits in lifespan and climbing ability.

The relationship of Amyotrophic Lateral Sclerosis, Parkinson’s disease, and other age-related neurodegenerative diseases with mitochondrial dysfunction has led to our study of the mitochondrial fission gene Drp1 in Drosophila melanogaster and aspects of aging. Previously, the Drp1 protein has been demonstrated to interact with the Drosophila Bcl-2 mitochondrial proteins, and Drp1 mutations can lead to mitochondrial dysfunction and neuronal loss. In this study, the Dopa decarboxylase-Gal4 (Ddc-Gal4) transgene was exploited to direct the expression of Drp1 and Drp1-RNAi transgenes in select neurons. Here, the knockdown of Drp1 seems to compromise locomotor function throughout life but does not alter longevity. The co-expression of Buffy suppresses the poor climbing induced by the knockdown of the Drp1 function. The consequences of Drp1 overexpression, which specifically reduced median lifespan and diminished climbing abilities over time, can be suppressed through the directed co-overexpression of pro-survival Bcl-2 gene Buffy or by the co-knockdown of the pro-cell death Bcl-2 homologue Debcl. Alteration of the expression of Drp1 acts to phenocopy neurodegenerative disease phenotypes in Drosophila, while overexpression of Buffy can counteract or rescue these phenotypes to improve overall health. The diminished healthy aging due to either the overexpression of Drp1 or the RNA interference of Drp1 has produced novel Drosophila models for investigating mechanisms underlying neurodegenerative disease.

Objective: Sequestosome 1 (p62/SQSTM1) is a multifunctional scaffold/adaptor protein encoded by the p62/SQSTM1 gene with function in cellular homeostasis. Mutations in the p62/SQSTM1 gene have been known to be associated with patients with Amyotrophic Lateral Sclerosis (ALS), Frontotemporal Dementia (FTD), and Parkinson Disease (PD). The aim of the present study was to create a novel model of human neurogenerative disease in Drosophila melanogaster by altering the expression of Ref(2)P, the Drosophila orthologue of the human p62/SQSTM1 gene. Ref(2)P expression was altered in all neurons, the dopaminergic neurons and in the motor neurons, with longevity and locomotor function assessed over time.Results: Inhibition of Ref(2)P resulted in a significantly increased median lifespan in the motor neurons, followed by a severe decline in motor skills. Inhibition of Ref(2)P in the dopaminergic neurons resulted in a significant, but minimal increase in median lifespan, accompanied by a drastic decline in locomotor function. Inhibition of Ref(2)P in the ddc-Gal4-expressing neurons resulted in a significant increase in median lifespan, while dramatically reducing motor function.

Background: Parkinson Disease (PD) and other neurodegenerative diseases have a significant relationship with mitochondrial dysfunction. The substantial effect of mitochondrial dynamics in PD has led us to study the role of the gene encoding the mitochondrial fission protein Drp1 in Drosophila models. Drp1 is a member of the highly conserved, dynamin family of protein encoding genes. Drp1 plays an essential role in the maintenance of the mitochondrial, peroxisomal, and endoplasmic reticulum (ER) dynamics, and has been found to regulate processes during homeostasis and cell survival.Results: The directed expression of Drp1 in Drosophila melanogaster neurons under the control of the Ddc-Gal4 transgene decreases the lifespan and compromises climbing ability over time. The directed inhibition of Drp1 produces a novel model of Parkinson Disease, as this causes little change in mean lifespan but a significant decrease in locomotor or climbing abilities. Interestingly, the loss of park dependent Drosophila model of PD is rescued by the directed inhibition of Drp1 .Conclusion: The compromised climbing abilities in flies with directed inhibition of Drp1 has produced a new model for Parkinson Disease and can be used to further investigate the mechanism(s) underlying PD and other neurodegenerative diseases. Interestingly, the combined inhibition of both Drp1 and park suppresses Parkinson Disease phenotypes and promotes survival.

Abstract Background: Valosin-Containing Protein (VCP) is an essential AAA+ ATPase with diverse functions within the cell. Mutations in the VCP gene have been detected in patients with familial amyotrophic lateral sclerosis (ALS). The aim of this study is to create a novel model of human neurodegenerative disease in Drosophila melanogaster by altering the expression of TER94, the Drosophila orthologue of the human VCP gene. TER94 expression was altered in all neurons, the dopaminergic neurons and in the motor neurons, with longevity and locomotor function assessed over time. Altered TER94 expression in combination with the altered expression of known Parkinson Disease (PD) genes was examined to investigate potential interactions.Results: Inhibition of TER94 altered median lifespan in a manner dependent upon the transgene selected for use and the tissue-specific expression directed by the Gal4 transgene selected. Locomotor ability was significantly reduced in all cases of TER94 inhibition tested. The inhibition of TER94 by two TER94-RNAi inhibitory transgenes, in the motor neurons via D42-Gal4 lead to increases in median lifespan, with one inhibitory transgene generating a slightly reduced lifespan. Inhibition of TER94 in the dopaminergic neurons resulted in a severe reduction in lifespan. The co-inhibition of TER94 and parkin in the neurons resulted in a major decline in lifespan by approximately 30%. While the inhibition of TER94 and the co-expression of alpha-synuclein in the neurons resulted in an increase in lifespan by approximately 28%. Conclusions: The inhibition of TER94 in the motor neurons is an interesting model of ALS, due to the small, but reduced lifespan coupled with a strong decline in locomotor function. The inhibition of TER94 in the dopaminergic neurons is a potential model of ALS, due to the reduction of both lifespan and locomotor function over time. The co-inhibition of TER94 and parkin in the neurons provides a promising novel model of neurodegenerative disease, displaying a great reduction in lifespan and in locomotor ability over time.

Background.Bax inhibitor-1 (BI-1) is an evolutionarily conserved cytoprotective transmembrane protein, that acts as a suppressor of Bax-induced apoptosis by regulation of endoplasmic reticulum (ER) stress-induced cell death.We knocked down BI-1 in the sensitive dopa decarboxylase (Ddc) expressing neurons of Drosophila melanogaster to investigate its neuroprotective functions.We additionally sought to rescue the BI-1-induced phenotypes by co-expression with the pro-survival Buffy and determined the effect of BI-1 knockdown on the neurodegenerative α-synuclein-induced Parkinson disease model. Methods.We used organismal assays to assess longevity of the flies to determine the effect of the altered expression of BI-1 in the Ddc-Gal4-expressing neurons by employing two RNAi transgenic fly lines.We measured the locomotor ability of these RNAi lines by computing the climbing indices of the climbing ability and compared them to a control line that expresses the lacZ transgene.Finally, we performed biometric analysis of the developing eye, where we counted the number of ommatidia and calculated the area of ommatidial disruption.Results.The knockdown of BI-1 in these neurons was achieved under the direction of the Ddc-Gal4 transgene and resulted in shortened lifespan and precocious loss of locomotor ability.The co-expression of Buffy, the Drosophila anti-apoptotic Bcl-2 homologue, with BI-1-RNAi resulted in suppression of the reduced lifespan and impaired climbing ability.Expression of human α-synuclein in Drosophila dopaminergic neurons results in neuronal degeneration, accompanied by the age-dependent loss in climbing ability.We exploited this neurotoxic system to investigate possible BI-1 neuroprotective function.The co-expression of α-synuclein with BI-1-RNAi results in a slight decrease in lifespan coupled with an impairment in climbing ability.In supportive experiments, we employed the neuron-rich Drosophila compound eye to investigate subtle phenotypes that result from altered gene expression.The knockdown of BI-1 in the Drosophila developing eye under the direction of the GMR-Gal4 transgene results in reduced ommatidia number and increased disruption of the ommatidial array.Similarly, the coexpression of BI-1-RNAi with Buffy results in the suppression of the eye phenotypes.The expression of αsynuclein along with the knockdown of BI-1 resulted in reduction of ommatidia number and more disruption of the ommatidial array.Conclusions.Knockdown of BI-1 in the dopaminergic neurons of Drosophila results in a shortened lifespan and premature loss in climbing ability, phenotypes that appear to be strongly associated with models of Parkinson disease in Drosophila, and which are suppressed upon overexpression of Buffy and worsened by co-expression with α-synuclein.This suggests that BI-1 is neuroprotective and its knockdown can be counteracted by the overexpression of the pro-survival Bcl-2 homologue.

BACKGROUND:The identification of a DNA variant in pyridoxal kinase (Pdxk) associated with increased risk to Parkinson disease (PD) gene led us to study the inhibition of this gene in the Dopa decarboxylase (Ddc)-expressing neurons of the well-studied model organism Drosophila melanogaster. The multitude of biological functions attributable to the vitamers catalysed by this kinase reveal an overabundance of possible links to PD, that include dopamine synthesis, antioxidant activity and mitochondrial function. Drosophila possesses a single homologue of Pdxk and we used RNA interference to inhibit the activity of this kinase in the Ddc-Gal4-expressing neurons. We further investigated any association between this enhanced disease risk gene with the established PD model induced by expression of α-synuclein in the same neurons. We relied on the pro-survival functions of Buffy, an anti-apoptotic Bcl-2 homologue, to rescue the Pdxk-induced phenotypes.RESULTS:To drive the expression of Pdxk RNA interference in DA neurons of Drosophila, we used Ddc-Gal4 which drives expression in both dopaminergic and serotonergic neurons, to result in decreased longevity and compromised climbing ability, phenotypes that are strongly associated with Drosophila models of PD. The inhibition of Pdxk in the α-synuclein-induced Drosophila model of PD did not alter longevity and climbing ability of these flies. It has been previously shown that deficiency in vitamers lead to mitochondrial dysfunction and neuronal decay, therefore, co-expression of Pdxk-RNAi with the sole pro-survival Bcl-2 homologue Buffy in the Ddc-Gal4-expressing neurons, resulted in increased survival and a restored climbing ability. In a similar manner, when we inhibited Pdxk in the developing eye using GMR-Gal4, we found that there was a decrease in the number of ommatidia and the disruption of the ommatidial array was more pronounced. When Pdxk was inhibited with the α-synuclein-induced developmental eye defects, the eye phenotypes were unaltered. Interestingly co-expression with Buffy restored ommatidia number and decreased the severity of disruption of the ommatidial array.CONCLUSIONS:Though Pdxk is not a confirmed Parkinson disease gene, the inhibition of this kinase recapitulated the PD-like symptoms of decreased lifespan and loss of locomotor function, possibly producing a new model of PD.

The mitochondrial calcium uptake 1 (MICU1) is a regulatory subunit of the mitochondrial calcium uniporter that plays an important role in calcium sensing. It contains two EF-hand domains that are well conserved across diverse species from protozoa to plants and metazoans. The loss of MICU1 function in mammals is attributed to several neurological disorders that involve movement dysfunction. The CG4495 gene in Drosophila melanogaster was identified as a putative homolog of MICU1 in the HomoloGene database of the National Centre for Biotechnology Information (NCBI). In agreement with previous studies that have shown the development of neurological disorders and movement defects in MICU1 loss-of-function organisms, we attempted to identify the function of CG4495/MICU1 in Drosophila neurons. We analyzed survival and locomotor ability of these flies and additionally performed biometric analysis of the Drosophila developing eye. The inducible RNA interference-mediated inhibition of CG4495/MICU1 in the Ddc-Gal4-expressing neurons of Drosophila presented with reduction in survival coupled with a precocious loss of locomotor ability. Since the pro-survival Bcl-2 family genes have been shown to be protective towards mitochondria, and CG4495/MICU1 has a mitochondrial targeting sequence, we attempted to rescue the phenotypes resulting from the inhibition of CG4495/MICU1 by overexpressing Buffy, the sole Bcl-2 homologue in Drosophila. The co-expression of CG4495/MICU1-RNAi along with Buffy resulted in the suppression of the phenotypes induced by the inhibition of CG4495/MICU1. Subsequently, the inhibition of CG4495/MICU1 in the Drosophila developing eye, a neuron-rich organ, resulted in reduced number of ommatidia and a highly fused ommatidial array. These developmental eye defects were rescued by the overexpression of Buffy. Our study suggests an important role for MICU1 in the normal function of neurons in Drosophila.

Background Bax inhibitor-1 (BI-1) is an evolutionarily conserved cytoprotective transmembrane protein that acts as a suppressor of Bax-induced apoptosis by regulation of endoplasmic reticulum stress-induced cell death. We knocked down BI-1 in the sensitive dopa decarboxylase (Ddc) expressing neurons of Drosophila melanogaster to investigate its neuroprotective functions. We additionally sought to rescue the BI-1-induced phenotypes by co-expression with the pro-survival Buffy and determined the effect of BI-1 knockdown on the neurodegenerative α-synuclein-induced Parkinson disease (PD) model. Methods We used organismal assays to assess longevity of the flies to determine the effect of the altered expression of BI-1 in the Ddc-Gal4-expressing neurons by employing two RNAi transgenic fly lines. We measured the locomotor ability of these RNAi lines by computing the climbing indices of the climbing ability and compared them to a control line that expresses the lacZ transgene. Finally, we performed biometric analysis of the developing eye, where we counted the number of ommatidia and calculated the area of ommatidial disruption. Results The knockdown of BI-1 in these neurons was achieved under the direction of the Ddc-Gal4 transgene and resulted in shortened lifespan and precocious loss of locomotor ability. The co-expression of Buffy, the Drosophila anti-apoptotic Bcl-2 homologue, with BI-1-RNAi resulted in suppression of the reduced lifespan and impaired climbing ability. Expression of human α-synuclein in Drosophila dopaminergic neurons results in neuronal degeneration, accompanied by the age-dependent loss in climbing ability. We exploited this neurotoxic system to investigate possible BI-1 neuroprotective function. The co-expression of α-synuclein with BI-1-RNAi results in a slight decrease in lifespan coupled with an impairment in climbing ability. In supportive experiments, we employed the neuron-rich Drosophila compound eye to investigate subtle phenotypes that result from altered gene expression. The knockdown of BI-1 in the Drosophila developing eye under the direction of the GMR-Gal4 transgene results in reduced ommatidia number and increased disruption of the ommatidial array. Similarly, the co-expression of BI-1-RNAi with Buffy results in the suppression of the eye phenotypes. The expression of α-synuclein along with the knockdown of BI-1 resulted in reduction of ommatidia number and more disruption of the ommatidial array. Conclusion Knockdown of BI-1 in the dopaminergic neurons of Drosophila results in a shortened lifespan and premature loss in climbing ability, phenotypes that appear to be strongly associated with models of PD in Drosophila, and which are suppressed upon overexpression of Buffy and worsened by co-expression with α-synuclein. This suggests that BI-1 is neuroprotective and its knockdown can be counteracted by the overexpression of the pro-survival Bcl-2 homologue.

Feeding is a complex behavior that is regulated by several internal mechanisms. Neuropeptides are able to survey quantities of stored energy and inform the organism if nutrient intake is required. In addition to this homeostatic regulation, a post-feeding reward system positively reinforces feeding. Slight adjustments to either system can tilt the balance to affect the energy reserves and survivorship in times of nutrient adversity. Neuropeptide F (NPF), a homolog of the mammalian neuropeptide Y, acts to induce feeding within the homeostatic regulation of this behavior. Drosophila and other insects bear a shorter form of NPF known as short NPF (sNPF) that can influence feeding. A neural hormone regulator, the dopamine transporter (DAT), works to clear dopamine from the synapses. This action may manipulate the post-feeding reward circuit in that lowered dopamine levels depress feeding, and excess dopamine levels encourage feeding. Here, we have overexpressed and impaired the activities of NPF, sNPF, and DAT in Drosophila, and we examined their ability to survive during conditions of amino acid starvation. Too much or too little NPF or sNPF, which are key players in homeostatic feeding regulation, leads to increased sensitivity to amino acid starvation and diminished survivorship when compared to controls. When DAT, a member of the post-feeding reward system, is either overexpressed or reduced via mutation, Drosophila has increased sensitivity to amino acid starvation. Taken together, these results indicate that subtle variation in the expression of key components of these systems impacts survivorship during adverse nutrient conditions.

Mutations in High temperature requirement A2 (HtrA2), also designated PARK13, which lead to the loss of its protease activity, have been associated with Parkinson's disease (PD). HtrA2 is a mitochondrial protease that translocates to the cytosol upon the initiation of apoptosis where it participates in the abrogation of inhibitors of apoptosis (IAP) inhibition of caspases. Here, we demonstrate that the loss of the HtrA2 function in the dopaminergic neurons of Drosophila melanogaster results in PD-like phenotypes, and we attempt to restore the age-dependent loss in locomotor ability by co-expressing the sole pro-survival Bcl-2 homologue Buffy. The inhibition of HtrA2 in the dopaminergic neurons of Drosophila resulted in shortened lifespan and impaired climbing ability, and the overexpression of Buffy rescued the reduction in lifespan and the age-dependent loss of locomotor ability. In supportive experiments, the inhibition of HtrA2 in the Drosophila eye results in eye defects, marked by reduction in ommatidia number and increased disruption of the ommatidial array; phenotypes that are suppressed by the overexpression of Buffy.

Background Parkinson disease (PD) is a debilitating movement disorder that afflicts 1–2% of the population over 50 years of age. The common hallmark for both sporadic and familial forms of PD is mitochondrial dysfunction. Mammals have at least twenty proapoptotic and antiapoptotic Bcl-2 family members, in contrast, only two Bcl-2 family genes have been identified in Drosophila melanogaster, the proapoptotic mitochondrial localized Debcl and the antiapoptotic Buffy. The expression of the human transgene α-synuclein, a gene that is strongly associated with inherited forms of PD, in dopaminergic neurons (DA) of Drosophila, results in loss of neurons and locomotor dysfunction to model PD in flies. The altered expression of Debcl in the DA neurons and neuron-rich eye and along with the expression of α-synuclein offers an opportunity to highlight the role of Debcl in mitochondrial-dependent neuronal degeneration and death. Results The directed overexpression of Debcl using the Ddc-Gal4 transgene in the DA of Drosophila resulted in flies with severely decreased survival and a premature age-dependent loss in climbing ability. The inhibition of Debcl resulted in enhanced survival and improved climbing ability whereas the overexpression of Debcl in the α-synuclein-induced Drosophila model of PD resulted in more severe phenotypes. In addition, the co-expression of Debcl along with Buffy partially counteracts the Debcl-induced phenotypes, to improve the lifespan and the associated loss of locomotor ability observed. In complementary experiments, the overexpression of Debcl along with the expression of α-synuclein in the eye, enhanced the eye ablation that results from the overexpression of Debcl. The co-expression of Buffy along with Debcl overexpression results in the rescue of the moderate developmental eye defects. The co-expression of Buffy along with inhibition of Debcl partially restores the eye to a roughened eye phenotype. Discussion The overexpression of Debcl in DA neurons produces flies with shortened lifespan and impaired locomotor ability, phenotypes that are strongly associated with models of PD in Drosophila. The co-expression of Debcl along with α-synuclein enhanced the PD-like phenotypes. The co-expression of Debcl along with Buffy suppresses these phenotypes. Complementary experiments in the Drosophila eye show similar trends during development. Taken all together these results suggest a role for Debcl in neurodegenerative disorders.

BACKGROUND:Mitochondrial porin, also known as the voltage-dependent anion channel (VDAC), is a multi-functional channel protein that shuttles metabolites between the mitochondria and the cytosol and implicated in cellular life and death decisions. The inhibition of porin under the control of neuronal Ddc-Gal4 result in short lifespan and in an age-dependent loss in locomotor function, phenotypes that are strongly associated with Drosophila models of Parkinson disease.METHODS:Loss of porin function was achieved through exploitation of RNA interference while derivative lines were generated by homologous recombination and tested by PCR. The UAS/Gal4 expression system was exploited with directed expression in neurons achieved with the use of the Dopa decarboxylase and in the developing eye with the Glass multiple reporter transgenes. Statistical analyses for ageing assay employed Log rank (Mantel-Cox) test, climbing indices were fitted with a non-linear curve and confidence intervals compared at 95%. Biometric analysis of the eye phenotypes was obtained by unpaired student T-test.RESULTS:The expression of α-synuclein in neuronal populations that include dopamine producing neurons under the control of Ddc-Gal4 produces a robust Parkinson disease model, and results in severely reduced lifespan and locomotor dysfunction. In addition, the porin-induced phenotypes are greatly suppressed when the pro-survival Bcl-2 homologue Buffy is overexpressed in these neurons and in the developing eye adding to the cellular advantages of altered expression of this anti-apoptotic gene. When we co-expressed α-synuclein along with porin, it results in a decrease in lifespan and impaired climbing ability. This enhancement of the α-synuclein-induced phenotypes observed in neurons was demonstrated in the neuron rich eye, where the simultaneous co-expression of porin-RNAi and α-synuclein resulted in an enhanced eye phenotype, marked by reduced number of ommatidia and increased disarray of the ommatidia.CONCLUSIONS:The inhibition of porin in dopaminergic neurons among others result in reduced lifespan and age-dependent loss in climbing ability, phenotypes that are suppressed by the overexpression of the sole pro-survival Bcl-2 homologue Buffy. The inhibition of porin phenocopies Parkinson disease phenotypes in Drosophila, while the overexpression of Buffy can counteract these phenotypes to improve the overall "healthspan" of the organism.

Lifeguard is an integral transmembrane protein that modulates FasL-mediated apoptosis by interfering with the activation of caspase 8. It is evolutionarily conserved, with homologues present in plants, nematodes, zebra fish, frog, chicken, mouse, monkey, and human. The Lifeguard homologue in Drosophila, CG3814, contains the Bax inhibitor-1 family motif of unknown function. Downregulation of Lifeguard disrupts cellular homeostasis and disease by sensitizing neurons to FasL-mediated apoptosis. We used bioinformatic analyses to identify CG3814, a putative homologue of Lifeguard, and knocked down CG3814/LFG expression under the control of the Dopa decarboxylase (Ddc-Gal4) transgene in Drosophila melanogaster neurons to investigate whether it possesses neuroprotective activity. Knockdown of CG3814/LFG in Ddc-Gal4-expressing neurons resulted in a shortened lifespan and impaired locomotor ability, phenotypes that are strongly associated with the degeneration and loss of dopaminergic neurons. Lifeguard interacts with anti-apoptotic Bcl-2 proteins and possibly pro-apoptotic proteins to exert its neuroprotective function. The co-expression of Buffy, the sole anti-apoptotic Bcl-2 gene family member in Drosophila, and CG3814/LFG by stable inducible RNA interference, suppresses the shortened lifespan and the premature age-dependent loss in climbing ability. Suppression of CG3814/LFG in the Drosophila eye reduces the number of ommatidia and increases disruption of the ommatidial array. Overexpression of Buffy, along with the knockdown of CG3814/LFG, counteracts the eye phenotypes. Knockdown of CG3814/LFG in Ddc-Gal4-expressing neurons in Drosophila diminishes its neuroprotective ability and results in a shortened lifespan and loss of climbing ability, phenotypes that are improved upon overexpression of the pro-survival Buffy.

Buffy suppresses these phenotypes.Complementary experiments in the Drosophila eye show similar trends during development.Taken all together these results suggest a role for debcl in neurodegenerative disorders.

Buffy suppresses these phenotypes.Complementary experiments in the Drosophila eye show similar trends during development.Taken all together these results suggest a role for debcl in neurodegenerative disorders.

Autophagy is a cellular mechanism implicated in the pathology of Parkinson's disease. The proteins Atg6 (Beclin 1) and Pi3K59F are involved in autophagosome formation, a key step in the initiation of autophagy. We first used the GMR-Gal4 driver to determine the effect of reducing the expression of the genes encoding these proteins on the developing Drosophila melanogaster eye. Subsequently, we inhibited their expression in D. melanogaster neurons under the direction of a Dopa decarboxylase (Ddc) transgene, and examined the effects on longevity and motor function. Decreased longevity coupled with an age-dependent loss of climbing ability was observed. In addition, we investigated the roles of these genes in the well-studied α-synuclein-induced Drosophila model of Parkinson's disease. In this context, lowered expression of Atg6 or Pi3K59F in Ddc-Gal4-expressing neurons results in decreased longevity and associated age-dependent loss of locomotor ability. Inhibition of Atg6 or Pi3K59F together with overexpression of the sole pro-survival Bcl-2 Drosophila homolog Buffy in Ddc-Gal4-expressing neurons resulted in further decrease in the survival and climbing ability of Atg6-RNAi flies, whereas these measures were ameliorated in Pi3K59F-RNAi flies.

Growth hormone-inducible transmembrane protein (GHITM) is an inner mitochondrial membrane protein that contains the Bax inhibitor-1 motif and is implicated in the regulation of mitochondrial morphology and especially cristae structure. The downregulation of GHITM results in fragmented mitochondria and the release of cytochrome c, while its upregulation delays the release of cytochrome c. We inhibited CG2076 the Drosophila GHITM homologue in the neurons using RNA interference and analysed the phenotypic consequences of this mitochondrial protein. The directed expression of GHITM-RNAi in neurons under the control of the Dopa decarboxylase (Ddc) transgene results in shortened lifespan and impaired climbing ability. The co-expression of Buffy, the only anti-apoptotic B cell lymphoma 2 (Bcl-2) protein in Drosophila, along with GHITM-RNAi results in suppression of the shortened lifespan and premature age-dependent loss in climbing ability. The inhibition of GHITM in the Drosophila eye results in decreased ommatidia number and elevated disruption of the ommatidial array, phenotypes that are rescued upon overexpression of Buffy. The inhibition of the mitochondrial located GHITM in the Ddc-Gal4-expressing neurons of Drosophila results in shortened lifespan and loss in climbing ability, phenotypes that are manifest of degeneration and death of dopaminergic neurons, and are improved upon overexpression of the pro-survival Buffy.