Transmembrane Protein 176B (TMEM176B)

The deduced 270-amino acid protein has a predicted molecular mass of 29.1 kD. Hydropathy analyses showed that LR8 contains 4 predicted transmembrane domains and a putative N-terminal signal sequence. Sequence analysis of an LR8 RT-PCR product from human lung fibroblast cDNA confirmed expression of LR8 sequence minus the predicted signal sequence. BLAST analysis also identified LR8 homologs in pig and mouse. Human and mouse LR8 proteins share 54% identity and 62% similarity. Northern blot analysis identified a 1.6-kb transcript with elevated expression in fibrotic lung specimens relative to normal lung tissue. Northern blot analysis also showed LR8 expression in dermal fibroblasts, but no expression in aortic smooth-muscle cells, umbilical vein endothelial cells, and neonatal foreskin epithelial cells.