A phylogenetically conserved hnRNP type A/B protein from squid brain. (23rd March 2019)

• Record Type: Journal Article
• Authors: Lopes, Gabriel Sarti; Lico, Diego Torrecillas Paula; Silva-Rocha, Rafael; de Oliveira, Renata Rocha; Sebollela, Adriano; Paçó-Larson, Maria Luisa; Larson, Roy Edward
• Is Part Of: Neuroscience letters. Volume 696(2019)
• Page Start: 219
• Page End: 224
• Publication Date: 2019-03-23
• Subjects: BSA bovine serum albumin -- RBPs RNA binding proteins -- hnRNPs heterogeneous nuclear ribonucleoproteins -- mRNA messenger RNA -- IP isoelectric point -- PAGE polyacrylamide gel electrophoresis -- PBS phosphate buffered saline -- RNP ribonucleoprotein -- RNP1/RNP2 core sequences of RNA recognition motifs -- SDS sodium dodecyl sulfate -- NeuN neuronal nuclei protein -- PABP poly-A binding protein -- GAPDH glyceraldehyde-3-phosphate dehydrogenase -- BDNF brain-derived neurotrophic factor; Squid hnRNP -- Nuclear localization sequence -- Cell stress granules -- Presynaptic terminal -- SH-SY5Y cells; Neurology -- Periodicals; Neurology -- Periodicals; Research -- Periodicals; Neurologie -- Périodiques; Neuroanatomie -- Périodiques; Neuropharmacologie -- Périodiques; Neurophysiologie -- Périodiques; Neurology; Periodicals; Electronic journals; 617.48
• DOI: 10.1016/j.neulet.2019.01.002
• Languages: English
• ISSNs: 0304-3940

Abstract

Highlights: Molecular structure and function of hnRNPA/B class of RNA-binding proteins are phylogenetically conserved. The propensity of squid hnRNPA/B-like Protein 2 stably dimerize may gives clues about the p65 protein. The corresponding M9 region of squid hnRNPA/B-like Protein 2 clearly has a role on its subcellular distribution. Stress induced cytoplasmic granules of squid hnRNPA/B-like Protein 2 may indicate a role of squid protein in stress response. Abstract: Eukaryotic mRNA precursors are co-transcriptionally assembled into ribonucleoprotein complexes. Heterogeneous nuclear ribonucleoprotein (hnRNP) complexes are involved in mRNA translocation, stability, subcellular localization and regulation of mRNA translation. About 20 major classes of hnRNPs have been identified in mammals. In a previous work, we characterized a novel, strongly-basic, RNA-binding protein (p65) in presynaptic terminals of squid neurons presenting homology with human hnRNPA/B type proteins, likely involved in local mRNA processing. We have identified and sequenced two hnRNPA/B-like proteins associated with tissue purified squid p65: Protein 1 (36.3 kDa, IP 7.1) and Protein 2 (37.6 kDa, IP 8.9). In the present work we generated an in silico, tridimensional, structural model of squid hnRNPA/B-like Protein 2, which showed highly conserved secondary and tertiary structure of RNA recognition motifs with human hnRNPA1 protein, as well as illustrated the potential for squid Protein 2 stable homodimerization. This was supported by biophysical measurements of bacterially expressed, recombinant protein. In addition, we induced expression of squid hnRNPA/B-like Protein 2 in human neuroblastoma cells (SH-SY5Y) and observed an exclusively nuclear localization, which depended on an intact C-terminal amino acid sequence and which relocated to cytoplasm particles containing PABP when the cells were challenged with sorbitol, suggesting an involvement with stress granule function.