SURF4

{{short description|Protein-coding gene humans}}

{{Infobox_gene}}

Surfeit locus protein 4 or Surf4 is a protein involved in regulating export of some proteins from the endoplasmic reticulum to the golgi bodies.{{cite journal|title=Endoplasmic reticulum composition and form: Proteins in and out |vauthors=Sun S, Tang X, Guo Y, Hu J |journal=Current Opinion in Cell Biology |volume=71 |date=August 2021 |pages=1–6 |doi=10.1016/j.ceb.2021.01.008|pmid=33611096 |s2cid=231987943 }}{{cite web|url=https://www.genecards.org/cgi-bin/carddisp.pl?gene=SURF4 |accessdate=8 June 2022 |title=SURF4 Gene - Surfeit 4}} Surf4 is involved in trafficking soluble (i.e. non-membrane-bound) proteins, namely lipoproteins and PCSK9. It recognizes cargo proteins via a three-amino-acid sequence near the N-termini. The related protein in yeast is called Erv29p.

This gene is named based on its location in the surfeit gene cluster, composed of six housekeeping genes that do not share sequence similarity. The encoded protein is a conserved integral membrane protein containing multiple putative transmembrane regions. Surf4's yeast homolog is directly required for packaging glycosylated pro-alpha-factor into COPII vesicles.{{cite web | title = Entrez Gene: SURF4 surfeit 4| url = https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=6836}}

Eliminating Surf4 in the liver reduces the amount of lipid in the plasma and prevents atherosclerosis in mice.