Chicken RNA-binding protein TIA-1 contributes to stress granule formation in chicken cells and tissues.

T-cell internal antigen-1 (TIA-1) plays roles in regulating alternative pre-mRNA splicing, mRNA translation, and stress granule (SG) formation in human cells. As an evolutionarily conserved response to environmental stress, SG has been reported to exist in various species. However, SG formation in chicken cells and the role of chicken TIA-1 (cTIA-1) in SG assembly has not been elucidated. In the present study, we cloned cTIA-1 and showed that cTIA-1 facilitates in the assembly of canonical SGs in both human and chicken cells. Overexpression of chicken prion-related domain (cPRD) of cTIA-1 that bore an N-terminal GFP tag (pntGFP-cPRD) or Flag tag (pFlag-cPRD) induced the production of typical SGs. However, C-terminal GFP tag (pctGFP-cPRD) induced significantly large cytoplasmic granules that were devoid of endogenous G3BP1 and remained stable when exposed to cycloheximide, indicating that these were not typical SGs, and pntGFP tag influences cPRD localization. Finally, endogenous cTIA-1 was determined to be recruited to SGs in chicken cells and tissues under environmental stress. Taken together, our studies provide evidence that chicken TIA-1 plays a role in canonical SG formation in chicken cells and tissues. Our findings also indicated that cPRD is necessary for SG aggregation.