FSP27

The CIDE-N domain is involved in homodimerization which is crucial for its function in promoting lipid exchange and transfer.

Lipid transferase specifically expressed in white adipose tissue, which promotes unilocular lipid droplet formation by mediating lipid droplet fusion (PubMed:18334488, PubMed:19843876, PubMed:20049731, PubMed:23399566, PubMed:30361435). Lipid droplet fusion promotes their enlargement, restricting lipolysis and favoring lipid storage (PubMed:18334488, PubMed:19843876, PubMed:20049731, PubMed:23399566). Localizes on the lipid droplet surface, at focal contact sites between lipid droplets, and mediates atypical lipid droplet fusion by undergoing liquid-liquid phase separation (LLPS) and promoting directional net neutral lipid transfer from the smaller to larger lipid droplets (PubMed:18334488, PubMed:19843876, PubMed:20049731, PubMed:23399566). The transfer direction may be driven by the internal pressure difference between the contacting lipid droplet pair (PubMed:18334488, PubMed:19843876, PubMed:20049731, PubMed:23399566). Its role in neutral lipid transfer and lipid droplet enlargement is activated by the interaction with PLIN1 (PubMed:23399566). May also act as a CEBPB coactivator in the white adipose tissue to control the expression of a subset of CEBPB downstream target genes, including SOCS1, SOCS3, TGFB1, TGFBR1, ID2 and XDH (By similarity). When overexpressed in preadipocytes, induces apoptosis or increases cell susceptibility to apoptosis induced by serum deprivation or TGFB treatment (PubMed:12429024).

In omental adipose tissue of obese patients matched for BMI, expression levels tend to correlate with insulin sensitivity. Expression is increased 2-3 fold in the group of patients with high insulin sensitivity, compared to the insulin-resistant group. This observation is consistent with the idea that triglyceride storage in adipocytes plays an important role in sequestering triglycerides and fatty acids away from the circulation and peripheral tissues, thus enhancing insulin sensitivity in liver and muscle. This effect is not significant in subcutaneous adipose tissue (PubMed:18509062). In subcutaneous adipose tissue of diabetic patients, tends to negatively correlate with body mass index and total fat mass, independently of insulin sensitivity (PubMed:18334488).

Lipodystrophy, familial partial, 5

FPLD5

A form of lipodystrophy characterized by loss of subcutaneous adipose tissue affecting limb, femorogluteal and subcutaneous abdominal fat, preservation of visceral, neck and axilliary fat, hepatomegaly, hepatic steatosis and insulin-resistant diabetes.

None

The disease is caused by variants affecting the gene represented in this entry.

Ubiquitinated and targeted to proteasomal degradation, resulting in a short half-life (about 15 minutes in 3T3-L1 cells). Protein stability depends on triaclyglycerol synthesis, fatty acid availability and lipid droplet formation.

Belongs to the CIDE family.

Expressed mainly in adipose tissue, small intestine, heart, colon and stomach and, at lower levels, in brain, kidney and liver.

• Lipid droplet
• Endoplasmic reticulum
• Nucleus
• Diffuses quickly on lipid droplet surface, but becomes trapped and clustered at lipid droplet contact sites, thereby enabling its rapid enrichment at lipid droplet contact sites.

FSP27, CIDEC, Lipid transferase CIDEC, Cell death activator CIDE-3, Cell death-inducing DFFA-like effector protein C, Fat-specific protein FSP27 homolog

• entrezGene:63924
• omim:612120
• swissprot:Q96AQ7

Proteins

Metabolism

26754Da