| activin A receptor, type IIA | |||||||
|---|---|---|---|---|---|---|---|
| Identifiers | |||||||
| Symbol | ACVR2A | ||||||
| Alt. symbols | ACVR2 | ||||||
| NCBI gene | 92 | ||||||
| HGNC | 173 | ||||||
| OMIM | 102581 | ||||||
| RefSeq | NM_001616 | ||||||
| UniProt | P27037 | ||||||
| Other data | |||||||
| Locus | Chr. 2q22.2-23.3 | ||||||
| |||||||
| activin A receptor, type IIB | |||||||
|---|---|---|---|---|---|---|---|
| Identifiers | |||||||
| Symbol | ACVR2B | ||||||
| NCBI gene | 93 | ||||||
| HGNC | 174 | ||||||
| OMIM | 602730 | ||||||
| RefSeq | NM_001106 | ||||||
| UniProt | Q13705 | ||||||
| Other data | |||||||
| Locus | Chr. 3p22 | ||||||
| |||||||
Theactivin type 2 receptors belong to a largerTGF-beta receptor family and modulate signals fortransforming growth factor beta ligands. These receptors are involved in a host ofphysiological processes including,growth,cell differentiation,homeostasis,osteogenesis,apoptosis and many other functions. There are two activin type two receptors:ACVR2A andACVR2B.
Despite the large amount of processes that these ligands regulate, they all operate through essentially the samepathway: A ligand binds to a type 2 receptor, which recruits and trans-phosphorylates a type I receptor. The type I receptor recruits areceptor regulated SMAD (R-SMAD) which it phosphorylates. The RSMAD then translocates to the nucleus where it functions as atranscription factor.
Severalligands that signal through the activin type 2 receptors regulatemuscle growth.[1]Myostatin, a TGF-beta superfamily member, is a negative regulator of muscle growth.[1] Myostatin binds to ACVR2B and to a lesser extent ACVR2A. In mice that were ACVR2A−/− (null)mutants there was an increase in all four muscle groups studied (pectoralis,triceps,quadriceps, andgastrocnemious/plantaris muscles).[1] Two of these muscle groups (pectoralis and triceps) were increased in ACVR2B−/− (null) mutants.[1]
Activin plays a significant role in reproduction. ACVR2 receptors are present in the testis during testicular development.[2] ACR2A and ACVR2B was found to be localized primarily in thegonocytes as well as insertoli cells.[2] These cells are responsive to both autocrine and paracrine activin B signaling, which controls their proliferation.[2] Cells of theepididymis also have ACVR2A receptors present. ACVR2B receptors were found to be localized in the rete testis.[2]
The ACVR2 gene is often found inactivated inprostate cancer and tumors withmicrosatellite instability.[3]
In a lab, it has been shown that truncated mutations in the ACVR2 gene causes a significant reduction in activin mediated cell signaling. In 58.1% of microsatellite unstable (MSI-H)colorectal cancers the ACVR2A gene has been found mutated. It also plays a role in non-MSI-H colorectal cancers.[4]