ORMDL1

Ceramides bind to ORMDL3 N-terminus and stabilize it in a conformation that physically restricts the accessibility of the substrates to their binding sites in the serine palmitoyltransferase (SPT) complex, hence inhibiting SPT catalytic activity. In the absence of ceramides, the N-terminus is flexible and permits substrate binding, thus liberating SPT from inhibition.

Plays an essential role in the homeostatic regulation of sphingolipid de novo biosynthesis by modulating the activity of the serine palmitoyltransferase (SPT) in response to ceramide levels (PubMed:20182505). When complexed to SPT, the binding of ceramides to its N-terminus stabilizes a conformation that block SPT substrate entry, hence preventing SPT catalytic activity. Through this mechanism, maintains ceramide levels at sufficient concentrations for the production of complex sphingolipids, but which prevents the accumulation of ceramides to levels that trigger apoptosis (By similarity).

Belongs to the ORM family.

Widely expressed. Expressed in adult and fetal heart, brain, lung, liver, skeletal muscle and kidney. Expressed in adult pancreas and placenta and in fetal spleen abd thymus. Expressed at intermediate level in pancreas, placenta and brain but low in skeletal muscle and lung.

• Endoplasmic reticulum membrane
• Multi-pass membrane protein

HSPC202, ORMDL1, ORM1-like protein 1, Adoplin-1

• entrezGene:94101
• omim:610073
• swissprot:Q9P0S3

Proteins

Cardiovascular

17371Da