Activin type 2 receptor

activin A receptor, type IIA
Identifiers
Symbol	ACVR2A
Alt. symbols	ACVR2
Entrez	92
HUGO	173
OMIM	102581
RefSeq	NM_001616
UniProt	P27037
Other data
Locus	Chr. 2 q22.2-23.3

activin A receptor, type IIB
Identifiers
Symbol	ACVR2B
Entrez	93
HUGO	174
OMIM	602730
RefSeq	NM_001106
UniProt	Q13705
Other data
Locus	Chr. 3 p22

The Activin type 2 receptors modulate signals for ligands belonging to the Transforming growth factor beta superfamily of ligands. These include: Activin (or Inhibin), Bone morphogenetic proteins and Nodal. They 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 two 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 II receptors regulate muscle growth.Myostatin, a TGF-beta superfamily member, is a negative regulator of muscle growth. 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 (, triceps, quadriceps, and gastrocnemious/plantaris muscles). Two of these muscle groups ( and triceps) were increased in ACVR2B ^−/− (null) mutants.

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