IGSF1
Description
The IGSF1 (immunoglobulin superfamily member 1) is a protein-coding gene located on chromosome X.
IGSF1, a plasma membrane glycoprotein, is encoded by the IGSF1 gene located on the X chromosome. Its function in normal cells remains unclear. It is a member of the immunoglobulin (Ig) superfamily and was initially predicted to have 12 Ig loops, a transmembrane domain, and a short cytoplasmic tail. However, during translation, IGSF1 is cleaved into amino- and carboxy-terminal domains (NTD and CTD, respectively). Only the CTD reaches the plasma membrane, while the NTD is retained within the endoplasmic reticulum (ER). Mutations in the IGSF1 gene disrupt the CTD's transport to the plasma membrane. These mutations cause IGSF1 deficiency syndrome, also known as central hypothyroidism/testicular enlargement (CHTE), affecting approximately 1 in 100,000 people, with a higher incidence in males.
IGSF1 appears to act as a coreceptor in inhibin signaling, but it does not bind inhibin with high affinity. It can block activin A signaling, both in the presence and absence of inhibin B. This protein is crucial for mediating the specific antagonistic effect of inhibin B on activin-stimulated transcription.
IGSF1 is also known as CHTE, IGCD1, IGDC1, INHBP, PGSF2, p120.
