STARD5

StAR-related lipid transfer (START) domain containing 5
Identifiers
Symbols STARD5; MGC10327
External IDs OMIM607050 MGI2156765 HomoloGene11346 GeneCards: STARD5 Gene
RNA expression pattern
More reference expression data
Orthologs
Species Human Mouse
Entrez 80765 170460
Ensembl ENSG00000172345 ENSMUSG00000046027
UniProt Q9NSY2 Q78RK2
RefSeq (mRNA) NM_030574 NM_023377.4
RefSeq (protein) NP_085051 NP_075866.2
Location (UCSC) Chr 15:
81.6 – 81.62 Mb
Chr 7:
90.78 – 90.8 Mb
PubMed search [1] [2]

StAR-related lipid transfer protein 5 is a protein that in humans is encoded by the STARD5 gene.[1][2] The protein is a 213 amino acids long, consisting almost entirely of a StAR-related transfer (START) domain. It is also part of the StarD4 subfamily of START domain proteins, sharing 34% sequence identity with STARD4.

Function

The protein is most prevalent in the kidney and the liver where it is found in Kupffer cells.[1][3] STARD5 binds both cholesterol and 25-hydroxycholesterol and appears to function to redistribute cholesterol to the endoplasmic reticulum with which the protein associates and/or the plasma membrane.[1][4][5] Increased levels of StarD5 increase free cholesterol in the cell.[4]

Cholesterol homeostasis is regulated, at least in part, by sterol regulatory element (SRE)-binding proteins (e.g., SREBP1) and by liver X receptors (e.g., LXRA). Upon sterol depletion, LXRs are inactive and SREBPs are cleaved, after which they bind promoter SREs and activate genes involved in cholesterol biosynthesis and uptake. Sterol transport is mediated by vesicles or by soluble protein carriers, such as steroidogenic acute regulatory protein (STAR). STAR is homologous to a family of proteins containing a 200- to 210-amino acid STAR-related lipid transfer (START) domain, including STARD5.[1][2]

References

  1. ^ a b c d Soccio RE, Adams RM, Romanowski MJ, Sehayek E, Burley SK, Breslow JL (May 2002). "The cholesterol-regulated StarD4 gene encodes a StAR-related lipid transfer protein with two closely related homologues, StarD5 and StarD6". Proc Natl Acad Sci U S A 99 (10): 6943–8. doi:10.1073/pnas.052143799. PMC 124508. PMID 12011452. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=124508. 
  2. ^ a b "Entrez Gene: STARD5 START domain containing 5". http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=80765. 
  3. ^ Rodriguez-Agudo D, Ren S, Hylemon PB, Montanez R, Redford K, Natarajan R, Medina MA, Gil G, Pandak WM (June 2006). "Localization of StarD5 cholesterol binding protein". J Lipid Res 47 (6): 1168–75. doi:10.1194/jlr.M500447-JLR200. PMID 16534142. 
  4. ^ a b Rodriguez-Agudo D, Ren S, Hylemon PB, Redford K, Natarajan R, Del Castillo A, Gil G, Pandak WM (August 2005). "Human StarD5, a cytosolic StAR-related lipid binding protein". J Lipid Res 46 (8): 1615–23. doi:10.1194/jlr.M400501-JLR200. PMID 15897605. 
  5. ^ Chen Y-C, Meier RK, Zheng S, Khundmiri SJ, Tseng MT, Lederer ED, Epstein PN, Clark BJ (August 2009). "Steroidogenic Acute Regulatory (StAR)-Related Lipid Transfer Domain Protein 5 (STARD5) Localization and Regulation in Renal Tubules". Am J Physiol Renal Physiol 297 (2): F380-8. doi:10.​1152/​ajprenal.​90433.​2008. PMID 19474188. 

Further reading