Hypoxia induces the PDZ domain-containing syntenin in the marine teleost Paralichthys olivaceus

Abstract

Syntenin is a scaffolding PDZ domain-containing protein with diverse biological activities, including organization of protein complexes in the plasma membrane, regulation of B-cell development, intracellular trafficking, synaptic transmission, and cancer metastasis. In the present study, we isolated and characterized the cDNA of the olive flounder Paralichthys olivaceus syntenin, designated PoSyntenin. The full-length CDS of PoSyntenin with 5'- and 3'-UTR sequences is 2618bp long and consists of a 909bp open reading frame preceded by a 161bp 5'-UTR and followed by a 1551bp 3'-UTR. The PoSyntenin cDNA encodes a polypeptide of 302 amino acids containing two PDZ domains, which shares 61-80% homology with those of other species, including humans. Expression of the PoSyntenin mRNA was detectable from 1day post-hatching and constitutively in the brain, spleen, intestine, stomach, eye, liver, kidney, and gill of normal conditioned fish. Expression of the PoSyntenin mRNA was upregulated in the eye, liver, kidney, spleen, brain, gill, and intestine of flounder under hypoxia and was increased by treatment with the hypoxia-mimic CoCl(2) (a HIF-1 inducer) in HINAE cells. Taken together, these results suggest that PoSyntenin is a hypoxia target gene that has a potential role in the hypoxia response mechanism of fish.