semenogelin-1; semenogelin I; SGI; contains: alpha-inhibin-92; alpha-inhibin-31; seminal basic protein (SEMG1, SEMG)

Function

• predominant protein in semen.
• participates in formation of a gel matrix entrapping the accessory gland secretions & ejaculated spermatozoa
• fragments of semenogelin &/or fragments of related proteins may contribute to activation of progressive sperm movements as the gel-forming proteins are fragmented by KLK3/PSA
• alpha-inhibin-92 & alpha-inhibin-31, derived from the proteolytic degradation of semenogelin, inhibit secretion of pituitary FSH transglutaminase substrate
• rapidly cleaved after ejaculation by KLK3/PSA, resulting in liquefaction of the semen coagulum & the progressive release of motile spermatozoa
• occurs in disulfide-linked complexes which may also contain 2 less abundant 71-kD & 76-kD semenogelin-related polypeptides

Structure

belongs to the semenogelin family

Compartment

secreted

Alternative splicing

named isoforms=2

Expression

seminal vesicle

More general terms

• secreted protein
• glycoprotein
• protein precursor

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=6406
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:6406
• OMIM: https://mirror.omim.org/entry/182140
• UniProt: http://www.uniprot.org/uniprot/P04279.html