SPHK1, Full Length (SPHK1) Human Active Protein

The protein encoded by this gene catalyzes the phosphorylation of sphingosine to form sphingosine-1-phosphate (S1P), a lipid mediator with both intra- and extracellular functions. Intracellularly, S1P regulates proliferation and survival, and extracellularly, it is a ligand for cell surface G protein-coupled receptors. This protein, and its product S1P, play a key role in TNF-alpha signaling and the NF-kappa-B activation pathway important in inflammatory, antiapoptotic, and immune processes. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2011]

SPHK1: Catalyzes the phosphorylation of sphingosine to form sphingosine 1-phosphate (SPP), a lipid mediator with both intra- and extracellular functions. Also acts on D-erythro-sphingosine and to a lesser extent sphinganine, but not other lipids, such as D,L-threo-dihydrosphingosine, N,N-dimethylsphingosine, diacylglycerol, ceramide, or phosphatidylinositol. Interacts with ACY1. Binds to calmodulin. Interacts with SPHKAP. Widely expressed with highest levels in adult liver, kidney, heart and skeletal muscle. 2 isoforms of the human protein are produced by alternative splicing.

Protein type: EC 2.7.1.91; Lipid Metabolism - sphingolipid; Kinase, lipid

Chromosomal Location of Human Ortholog: 17q25.2

Cellular Component: synaptic vesicle; axon; cytoplasm; plasma membrane; nucleus; cytosol

Molecular Function: D-erythro-sphingosine kinase activity; calmodulin binding; protein binding; DNA binding; protein phosphatase 2A binding; sphinganine kinase activity; magnesium ion binding; diacylglycerol kinase activity; ATP binding; NAD+ kinase activity

Biological Process: protein folding; positive regulation of NF-kappaB import into nucleus; female pregnancy; positive regulation of mitotic cell cycle; signal transduction; positive regulation of neurotransmitter secretion; activation of NF-kappaB transcription factor; 'de novo' posttranslational protein folding; response to magnesium ion; positive regulation of fibroblast proliferation; regulation of interleukin-1 beta production; protein kinase C activation; positive regulation of smooth muscle contraction; inflammatory response; blood vessel development; sphingolipid metabolic process; sphingolipid biosynthetic process; cyclooxygenase pathway; calcium-mediated signaling; sphingosine metabolic process; cellular response to starvation; lipid phosphorylation; positive regulation of cell growth; response to ATP; positive regulation of angiogenesis; cellular protein metabolic process; positive regulation of protein ubiquitination; brain development; positive regulation of protein amino acid phosphorylation; response to progesterone stimulus; vascular endothelial growth factor receptor signaling pathway; response to amine stimulus; sphingoid catabolic process; negative regulation of apoptosis; positive regulation of cell migration