Regulation of expression of SG2NA isoforms in human cancer cell lines

Abstract

The Striatin family members (Striatin, SG2NA and Zinedin) have characteristic protein‐protein interaction domains as a caveolin‐binding domain, a coiled‐coil motif and a calmodulin‐binding domain at its N‐terminus and WD40 domain at carboxyl end. SG2NA was first reported in Lung and Bladder cancer patient serum as a Nuclear Autoantigen and its expression was found to be up regulated during the S and G2 phase of cell cycle. Mouse SG2NA generates five isoforms (87, 82, 78, 52 and 35kDas) by alternative splicing, intron retention and RNA editing. SG2NA isoforms are differentially expressed in mouse tissues viz., brain, heart, lung, liver and skeletal muscle. Besides alternative splicing and polyadenylation, sg2na expression is also regulated by post‐translational stability as its dephosphorylated form is more stable than the phosphorylated form. Further its role in Cancer progression and survival was established by its knockdown study. In the present study two splice variants (78 kDa and 87 kDa) of human sg2na were characterized. Further the expression of SG2NA isoforms in different human cancer cell lines (HEK293T, A549, H1299, HepG2, Hep3B, DU145, HELA) were assessed at the protein and RNA level which shows dyanamic expression. The expression of SG2NA isoforms varies among different cancer cell lines. In case of human cancer cell lines the expression of larger isoform i.e. 87 kDa was prominent unlike mouse which suggests that this SG2NA isoform in human is not undergoing proteasomal degradation. The ambiguity between mRNA and protein level in different cancer cell lines indicate its regulation at the post‐transcriptional or post‐translation level. There was no effect of proteasome inhibition on the stability of SG2NA in all the cells tested. The post‐transcriptional regulation study of SG2NA in different cancer cell lines would be a useful to show its expression and role in cancer progression.Support or Funding InformationDBT‐BUILDER, Government of India, awarded to the Jawaharlal Nehru University.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.