PAPSS1

Domain

The N-terminal first 50 residues are required for inhibition by the substrate adenylyl sulfate.

Function

Bifunctional enzyme with both ATP sulfurylase and APS kinase activity, which mediates two steps in the sulfate activation pathway. The first step is the transfer of a sulfate group to ATP to yield adenosine 5'-phosphosulfate (APS), and the second step is the transfer of a phosphate group from ATP to APS yielding 3'-phosphoadenylylsulfate (PAPS: activated sulfate donor used by sulfotransferase). In mammals, PAPS is the sole source of sulfate; APS appears to be only an intermediate in the sulfate-activation pathway (PubMed:14747722, PubMed:9576487, PubMed:9648242, PubMed:9668121). Required for normal biosynthesis of sulfated L-selectin ligands in endothelial cells (PubMed:9576487).

Pathway

Sulfur metabolism; sulfate assimilation.

Sequence Similarities

In the N-terminal section; belongs to the APS kinase family.

In the C-terminal section; belongs to the sulfate adenylyltransferase family.

Tissue Specificity

Expressed in testis, pancreas, kidney, thymus, prostate, ovary, small intestine, colon, leukocytes and liver. Also expressed in high endothelial venules (HEV) cells and in cartilage.

Alternative names

ATPSK1, PAPSS, PAPSS1, Bifunctional 3'-phosphoadenosine 5'-phosphosulfate synthase 1, PAPS synthase 1, PAPSS 1, Sulfurylase kinase 1, SK 1, SK1

Database links

swissprot:O43252 swissprot:O95340 entrezGene:9060 omim:603262 entrezGene:9061