Transforming Growth Factor Beta Receptor Associated Protein 1 (TGFbRAP1)

Members of the transforming growth factor-beta (TGFB) family act through type II membrane receptor serine-threonine kinases, which then recruit and transphosphorylate type I receptor serine-threonine kinases .Binding analysis indicated that TRAP1 interacted with activated TGFBR1 but not with wildtype, inactive TGFBR1. TRAP2 only interacted with activated TGFBR1 that also had the leu193-to-ala and pro194-to-ala mutations, which removed FKBP1A binding. The deduced 860-amino acid TRAP1 protein contains multiple phosphorylation and myristoylation sites. Northern blot analysis revealed ubiquitous expression of 4.4- and 6.0-kb TRAP1 transcripts, with lower abundance in lung and liver. Functional analysis suggested that a partial TRAP1 cDNA could act as an inhibitor of TGFB signaling.