Genomic Structure And Expression Of Lestd1, A Seven-Transmembrane-Domain Protein-Encoding Gene Specifically Expressed In Tomato Pollen

The tomato gene Lestd1 encodes for a seven-transmembrane-domain (STD), 238amino-acid-long protein whose expression is restricted to maturing pollen grains. Lestd1 belongs to a subfamily of STD proteins that is represented in metazoa and plants, but is missing from prokaryotes and fungi genomes. Similar genes in plants, nematodes, insects, and mammals maintain most of the splice junction sites, which are located at the boundaries of the transmembrane domains. Promoter analysis shows that a 550-base-pair-long sequence upstream to the translation initiation codon is sufficient to confer organ specificity both in tomato and tobacco.