Perilipin-4

Perilipin 4, also known as S3-12, is a protein that in humans is encoded by the PLIN4 gene on chromosome 19.[5][6] It is highly expressed in white adipose tissue, with lower expression in heart, skeletal muscle, and brown adipose tissue.[7] PLIN4 coats lipid droplets in adipocytes to protect them from lipases.[8][9] The PLIN4 gene may be associated with insulin resistance and obesity risk.[10]

PLIN4
Identifiers
AliasesPLIN4, KIAA1881, S3-12, perilipin 4
External IDsOMIM: 613247 MGI: 1929709 HomoloGene: 69311 GeneCards: PLIN4
Orthologs
SpeciesHumanMouse
Entrez

729359

57435

Ensembl

ENSG00000167676

ENSMUSG00000002831

UniProt

Q96Q06

O88492

RefSeq (mRNA)

NM_020568
NM_001372234

RefSeq (protein)

NP_001354797

NP_065593
NP_001359163

Location (UCSC)Chr 19: 4.5 – 4.52 MbChr 17: 56.41 – 56.42 Mb
PubMed search[3][4]
Wikidata
View/Edit HumanView/Edit Mouse

Structure

Gene

The PLIN4 gene resides on chromosome 19 at the band 19p13.3 and contains 9 exons.[5]

Protein

This protein belongs to the perilipin family and contains 27 33-amino acid approximate tandem repeats.[11] It is also one of the perilipin members of the PATS (PLIN, ADFP, TIP47, S3-12) family, which is named after structural proteins that share high amino acid sequence similarity and associate with lipid droplets.[6] It shares a conserved C-terminal of 14 amino acid residues that folds into a hydrophobic cleft with other PATS members; however, it is missing the conserved N-terminal region of approximately 100 amino acid residues. Within the sequence of 33-amino acid repeats, PLIN4 contains a long stretch of imperfect 11-mer repeats predicted to form amphipathic helices with three helical turns per 11 amino acid residues. This 11-mer repeats tract is proposed to anchor the protein to the phospholipid monolayer of lipid droplets for its assembly, though no targeting sequence has yet been found in PLIN4.[7]

Function

PLIN4 is a member of the perilipin family, a group of proteins that coat lipid droplets in adipocytes,[8] the adipose tissue cells that are responsible for storing fat. Perilipin acts as a protective coating from the body’s natural lipases, such as hormone-sensitive lipase,[9] which break triglycerides into glycerol and free fatty acids for use in metabolism, a process called lipolysis.[12] In humans, perilipin is expressed as 5 different isoforms; it is currently understood that the level of expression for each isoform is dependent on factors such as sex, body mass index, and level of endurance exercise.[13]

PLIN4 is hyperphosphorylated by PKA following β-adrenergic receptor activation. Phosphorylated perilipin changes conformation, exposing the stored lipids to hormone-sensitive lipase-mediated lipolysis. Although PKA also phosphorylates hormone-sensitive lipase, which can increase its activity, the more than 50-fold increase in fat mobilization (triggered by epinephrine) is primarily due to perilipin phosphorylation.

Clinical significance

The proteins in the Perilipin family are crucial regulators of lipid storage.[12] PLIN4 expression is elevated in obese animals and humans.

The PLIN4 gene, along with PLIN2, PLIN3, and PLIN5, have been associated with variance in body-weight regulation and may be a genetic influence on obesity risk in humans.[10]

Interactions

PLIN4 has been shown to interact with Caspase 8 and Ubiquitin C.[14]

References
  1. GRCh38: Ensembl release 89: ENSG00000167676 - Ensembl, May 2017
  2. GRCm38: Ensembl release 89: ENSMUSG00000002831 - Ensembl, May 2017
  3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. "Entrez Gene: Perilipin 4".
  6. Cusano NE, Kiel DP, Demissie S, Karasik D, Adrienne Cupples L, Corella D, Gao Q, Richardson K, Yiannakouris N, Ordovas JM (February 2012). "A Polymorphism in a gene encoding Perilipin 4 is associated with height but not with bone measures in individuals from the Framingham Osteoporosis Study". Calcified Tissue International. 90 (2): 96–107. doi:10.1007/s00223-011-9552-7. PMC 3628693. PMID 22210160.
  7. Brasaemle DL (December 2007). "Thematic review series: adipocyte biology. The perilipin family of structural lipid droplet proteins: stabilization of lipid droplets and control of lipolysis". Journal of Lipid Research. 48 (12): 2547–59. doi:10.1194/jlr.R700014-JLR200. PMID 17878492.
  8. Greenberg AS, Egan JJ, Wek SA, Garty NB, Blanchette-Mackie EJ, Londos C (June 1991). "Perilipin, a major hormonally regulated adipocyte-specific phosphoprotein associated with the periphery of lipid storage droplets". The Journal of Biological Chemistry. 266 (17): 11341–6. doi:10.1016/S0021-9258(18)99168-4. PMID 2040638.
  9. Wong K (2000-11-29). "Making Fat-proof Mice". Scientific American. Retrieved 2009-05-22.
  10. Soenen S, Mariman EC, Vogels N, Bouwman FG, den Hoed M, Brown L, Westerterp-Plantenga MS (March 2009). "Relationship between perilipin gene polymorphisms and body weight and body composition during weight loss and weight maintenance". Physiology & Behavior. 96 (4–5): 723–8. doi:10.1016/j.physbeh.2009.01.011. PMID 19385027. S2CID 24747708.
  11. Universal protein resource accession number Q96Q06 for "PLIN4 - Perilipin-4 - Homo sapiens - PLIN4 gene & protein" at UniProt.
  12. Wolins NE, Skinner JR, Schoenfish MJ, Tzekov A, Bensch KG, Bickel PE (September 2003). "Adipocyte protein S3-12 coats nascent lipid droplets". The Journal of Biological Chemistry. 278 (39): 37713–21. doi:10.1074/jbc.M304025200. PMID 12840023.
  13. Peters SJ, Samjoo IA, Devries MC, Stevic I, Robertshaw HA, Tarnopolsky MA (August 2012). "Perilipin family (PLIN) proteins in human skeletal muscle: the effect of sex, obesity, and endurance training". Applied Physiology, Nutrition, and Metabolism. 37 (4): 724–35. doi:10.1139/h2012-059. PMID 22667335.
  14. "PLIN4 Results Summary". BioGrid. Tyerslab.com. Retrieved 18 May 2015.

Further reading

This article incorporates text from the United States National Library of Medicine, which is in the public domain.

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.