immunoglobulin superfamily member 1 (inhibin-binding protein, inhBP, immunoglobulin-like domain-containing protein 1, Pituitary gland specific factor 2, p120, IGSF1, IGDC1, KIAA0364, PGSF2)

Function

• seems to be a coreceptor in inhibin signaling, but seems not to be a high-affinity inhibin receptor
• antagonizes activin A signaling in the presence or absence of inhibin B (putative)
• necessary to mediate a specific antagonistic effect of inhibin B on activin-stimulated transcription
• interacts with INHA (putative)
• interacts with ACVR1B, interaction appears to be ligand- dependent as it is diminished by inhibin B & activin A
• interacts with ACVR2A, ACVR2B, ACVRL1 & BMPR1B

Structure

• contains 12 Ig-like C2-type domain (immunoglobulin-like)

Compartment

• isoforms 1 & 2: membrane
• isoform 3: secreted (putative)

Alternative splicing

• named isoforms=3
• additional isoforms seem to exist

Expression

• highly expressed in pancreas, testis & fetal liver
• moderately expressed in heart, prostate & small intestine
• expressed at very low levels in brain, thymus, ovary, colon, fetal lung & fetal kidney
• expressed in muscle
• isoform 3 is expressed in pituitary gland

More general terms

• glycoprotein
• membrane protein
• immunoglobulin superfamily protein

Database

• OMIM: https://mirror.omim.org/entry/300137
• UniProt: http://www.uniprot.org/uniprot/Q8N6C5.html