Activin receptor type-1B is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

that in humans is encoded by the ''ACVR1B''

gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

. ACVR1B or ALK-4 acts as a transducer of activin or activin-like ligands (e.g., inhibin) signals. Activin binds to either

ACVR2A Activin receptor type-2A is a protein that in humans is encoded by the ''ACVR2A'' gene. ACVR2A is an activin type 2 receptor. Function This gene encodes activin A type II receptor. Activins are dimeric growth and differentiation factors which ...

ACVR2B Activin receptor type-2B is a protein that in humans is encoded by the ''ACVR2B'' gene. ACVR2B is an activin type 2 receptor. Function Activins are dimeric growth and differentiation factors which belong to the transforming growth factor-bet ...

and then forms a complex with ACVR1B. These go on to recruit the R-SMADs

SMAD2 Mothers against decapentaplegic homolog 2 also known as SMAD family member 2 or SMAD2 is a protein that in humans is encoded by the ''SMAD2'' gene. MAD homolog 2 belongs to the SMAD, a family of proteins similar to the gene products of the ''Dros ...

SMAD3 Mothers against decapentaplegic homolog 3 also known as SMAD family member 3 or SMAD3 is a protein that in humans is encoded by the SMAD3 gene. SMAD3 is a member of the SMAD family of proteins. It acts as a mediator of the signals initiated by t ...

. ACVR1B also transduces signals of

nodal Nodal homolog is a secretory protein that in humans is encoded by the ''NODAL'' gene which is located on chromosome 10q22.1. It belongs to the transforming growth factor beta superfamily (TGF-β superfamily). Like many other members of this superf ...

, GDF-1, and Vg1; however, unlike activin, they require other coreceptor molecules such as the protein

Cripto Cripto is an EGF-CFC or epidermal growth factor-CFC, which is encoded by the Cryptic family 1 gene. Cryptic family protein 1B is a protein that in humans is encoded by the ''CFC1B'' gene. Cryptic family protein 1B acts as a receptor for the TGF be ...

Function

Activins are dimeric growth and differentiation factors which belong to the transforming growth factor-beta (TGF-beta) superfamily of structurally related signaling proteins. Activins signal through a heteromeric complex of receptor serine kinases which include at least two type I (I and IB) and two type II (II and IIB) receptors. These receptors are all transmembrane proteins, composed of a ligand-binding extracellular domain with a cysteine-rich region, a transmembrane domain, and a cytoplasmic domain with predicted serine/threonine specificity. Type I receptors are essential for signaling, and type II receptors are required for binding ligands and for expression of type I receptors. Type I and II receptors form a stable complex after ligand binding, resulting in phosphorylation of type I receptors by type II receptors. This gene encodes activin A type IB receptor, composed of 11 exons. Alternative splicing and alternative polyadenylation result in 3 fully described transcript variants. The mRNA expression of variants 1, 2, and 3 is confirmed, and a potential fourth variant contains an alternative exon 8 and lacks exons 9 through 11, but its mRNA expression has not been confirmed.

Interactions

ACVR1B has been shown to

interact Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...

with *

, and

Function

Interactions

References

External links

Further reading