Surfeit locus protein 4 (SURF4)

The protein contains 269 amino acids for an estimated molecular weight of 30394 Da.

 

May play a role in the maintenance of the architecture of the endoplasmic reticulum-Golgi intermediate compartment and of the Golgi. (updated: Oct. 10, 2018)

Protein identification was indicated in the following studies:

  1. Lange and co-workers. (2014) Annotating N termini for the human proteome project: N termini and Nα-acetylation status differentiate stable cleaved protein species from degradation remnants in the human erythrocyte proteome. J Proteome Res. 13(4), 2028-2044.
  2. Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
  3. D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
  4. Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.

Methods

The following articles were analysed to gather the proteome content of erythrocytes.

The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.

PublicationIdentification 1Uniprot mapping 2Not mapped /
Obsolete
TrEMBLSwiss-Prot
Goodman (2013)2289 (gene list)227853205992269
Lange (2014)123412347281224
Hegedus (2015)2638262202352387
Wilson (2016)165815281702911068
d'Alessandro (2017)18261817201815
Bryk (2017)20902060101081942
Chu (2018)18531804553621387

1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry

The compilation of older studies can be retrieved from the Red Blood Cell Collection database.

The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.

No sequence conservation computed yet.

This protein is annotated as membranous in Gene Ontology, is predicted to be membranous by TOPCONS.


Interpro domains
Total structural coverage: 0%
Model score: 45

(right-click above to access to more options from the contextual menu)

The reference OMIM entry for this protein is 185660

Surfeit 4; surf4
Erv29, s. cerevisiae, homolog of; erv29

For background information on the surfeit genes, see SURF1 (185620).

CLONING

Using PCR with primers based on the sequence of mouse Surf4 to screen a HeLa cell cDNA library, Reeves and Fried (1995) obtained a cDNA encoding human SURF4. The deduced 269-amino acid protein, which is 60% and 99% identical to the worm and mouse proteins, respectively, contains 7 transmembrane segments, a predicted luminal N terminus, multiple phosphorylation sites, and a double-lysine retrieval motif at the C terminus. Immunoblot analysis showed expression of a 30-kD membrane protein. Immunofluorescence microscopy demonstrated cytoplasmic expression. Using Northern blot analysis, Garson et al. (1996) detected 3 variants of mouse Surf4 that were ubiquitously expressed, although the levels of each transcript varied between tissues.

GENE FUNCTION

Belden and Barlowe (2001) showed that Erv29, the yeast homolog of SURF4, is directly required for packaging glycosylated pro-alpha-factor (Gpaf) into COPII (see COPA; 601924) vesicles. Subcellular fractionation experiments indicated that Erv29 is equally distributed between endoplasmic reticulum (ER) and Golgi membranes. Increased expression of Erv29 in the ER alleviated the accumulation of Gpaf. Belden and Barlowe (2001) proposed that Erv29 binds to fully folded Gpaf and probably to other soluble secretory cargo in the ER, after which the Erv29-cargo complexes are packaged into COPII vesicles for transport to the Golgi complex. The authors noted that similar mechanisms have been postulated for ERGIC1 (LMAN1; 601567).

GENE STRUCTURE

Duhig et al. (1998) stated that the 5-prime end of each of the surfeit genes, including SURF4, is contained within a CpG island. Although the mouse Surf2 (185630) and Surf4 genes overlap at their 3-prime ends, human SURF2 and SURF4 are separated by 302 bp due to a much shorter 3-prime UTR in the human SURF2 gene.

MAPPING

By contig analysis, Duhig et al. (1998) mapped the SURF4 gene to the telomeric end of the surfeit locus on chromosome 9q34. ... More on the omim web site

Subscribe to this protein entry history

June 30, 2020: Protein entry updated
Automatic update: OMIM entry 185660 was added.

Dec. 10, 2018: Protein entry updated
Automatic update: model status changed

Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).