A novel SDS-stable dimer of a heterogeneous nuclear ribonucleoprotein at presynaptic terminals of squid neurons

•We identified a novel SDS-stable dimer of hnRNPA/B-like protein in squid pre-synaptic terminals.•Mono- and dimeric hnRNPA/B-like proteins were differentially associated with cellular components.•hnRNPA/B-like protein localized with synaptic vesicle protein Sv2 and RNA-binding protein ELAV.•Data mining into squid databases illustrated the complexity of the hnRNPA/B subfamily.•Analysis of the stability of the hnRNPA/B-like dimer may give clues to misfolding in disease states.