activin A receptor, type IIA | |||||||
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Identifiers | |||||||
Symbol | ACVR2A | ||||||
Alt. symbols | ACVR2 | ||||||
NCBI gene | 92 | ||||||
HGNC | 173 | ||||||
OMIM | 102581 | ||||||
RefSeq | NM_001616 | ||||||
UniProt | P27037 | ||||||
Other data | |||||||
Locus | Chr. 2 q22.2-23.3 | ||||||
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activin A receptor, type IIB | |||||||
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Identifiers | |||||||
Symbol | ACVR2B | ||||||
NCBI gene | 93 | ||||||
HGNC | 174 | ||||||
OMIM | 602730 | ||||||
RefSeq | NM_001106 | ||||||
UniProt | Q13705 | ||||||
Other data | |||||||
Locus | Chr. 3 p22 | ||||||
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The activin type 2 receptors belong to a larger TGF-beta receptor family and modulate signals for transforming growth factor beta ligands. These receptors are involved in a host of physiological processes including, growth, cell differentiation, homeostasis, osteogenesis, apoptosis and many other functions. There are two activin type two receptors: ACVR2A and ACVR2B.
Despite the large amount of processes that these ligands regulate, they all operate through essentially the same pathway: A ligand binds to a type 2 receptor, which recruits and trans-phosphorylates a type I receptor. The type I receptor recruits a receptor regulated SMAD (R-SMAD) which it phosphorylates. The RSMAD then translocates to the nucleus where it functions as a transcription factor.
Several ligands that signal through the activin type 2 receptors regulate muscle 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, and gastrocnemious/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 the gonocytes as well as in sertoli cells.[2] These cells are responsive to both autocrine and paracrine activin B signaling, which controls their proliferation.[2] Cells of the epididymis also have ACVR2A receptors present. ACVR2B receptors were found to be localized in the rete testis.[2]
The ACVR2 gene is often found inactivated in prostate cancer and tumors with microsatellite 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]