Biochemical and subcellular characterization of a squid hnRNPA/B-like protein in osmotic stress activated cells reflects molecular properties conserved in this protein family

Abstract

In previous works, we characterized a novel, strongly basic, squid hnRNPA/B-like Protein 2 in presynaptic terminals of squid neurons. Here, we show that squid hnRNPA/B-like Protein 2 are exclusively nuclear localization and relocated to cytoplasmic granules containing hnRNPA1 and Poly-A binding protein-1 (PABP-1) when the cells are treated with sorbitol. Also, we show an interaction of hnRNPA/B like Protein 2 with squid RNA, its interfered with dynamic of formation of hnRNPA/B like Protein 2 dimers, whereas possibly involved disulfide bounds and postranslations modification in a distinct stage of dimers formation. An understanding of the molecular and biochemical mechanisms involved in the stability of the dimeric form, and the regulation of the transition between monomeric and dimeric forms may bring insights into evolution of several neurodegenerative diseases. HighlightsO_LIWe identified monomeric (p37) and dimeric (p65) forms of squid hnRNPA/B-like Protein 2 in squid optic lobes C_LIO_LIOur data indicate a conserved structure and cellular properties of squid hnRNPA/B-like Protein 2 and human hnRNPA1 protein colocalizing with PABP into stress granules (SGs) C_LIO_LIThe stability of hnRNPA/B-like dimers involved the squid RNAs and disulfide bonds to promote higher SDS-stable dimers formation C_LIO_LIAn understanding of the transition between monomeric and dimeric forms of squid hnRNPA/B-like Protein 2 may give clues to misfolding processes in neuropathologies C_LI