activin receptor type-1B; ACTR-IB; serine/threonine protein kinase receptor R2; SKR2; activin receptor-like kinase 4; ALK-4 (ACVR1B, ACVRLK4)

Function

• on ligand binding, forms a receptor complex consisting of 2 type II & 2 type I transmembrane serine/threonine kinases
• type II receptors phosphorylate & activate type I receptors which autophosphorylate, then bind & activate SMAD transcriptional regulators
• interacts with AIP1
• part of a complex consisting of AIP1, ACVR2A, ACVR1B & SMAD3 (putative)

Cofactor: Mg+2 or Mn+2 (putative)

Structure

• belongs to the protein kinase superfamily, TKL Ser/Thr protein kinase family, TGFB receptor subfamily
• contains 1 GS domain
• contains 1 protein kinase domain

Compartment

membrane

Alternative splicing

named isoforms=3

Expression

• expressed in many tissues
• most strongly in kidney, pancreas, brain, lung, & liver

Notes

variant in position: 478:R->H

More general terms

• activin receptor
• activin receptor like kinase (ALK)
• phosphoprotein
• glycoprotein

Database

• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:91
• OMIM: https://mirror.omim.org/entry/601300
• UniProt: http://www.uniprot.org/uniprot/P36896.html