In previous works, we identified a RNA-binding protein in presynaptic terminal of squid neurons, which is likely involved in local mRNA processing. Evidences indicate this strongly basic protein, called p65, is an SDS-stable dimer protein composed of ~ 37 kDa hnRNPA/B-like subunits. The function of p65 in presynaptic regions is not well understood. In this work, we showed p65 and its subunit p37 are concentrated in RNA-enriched regions in synaptosomes. We performed in vitro binding studies with a recombinant protein and showed its propensity to selectively bind actin mRNA at the squid presynaptic terminal. Biochemical analysis using lysed synaptosomes suggested RNA integrity may affect p65 and p37 functions. Mass spectrometry analysis of oligo(dT) pull down indicated squid hnRNPA1, hnRNPA1-like 2, hnRNPA3 and ELAV-like proteins as candidates to interact with p65 and p37 forming a ribonucleoprotein complex, suggesting a role of squid hnRNPA/B-like proteins in site-specific RNA processing.

中文翻译：

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鱿鱼神经元突触前末端的hnRNPA / B样蛋白选择性RNA相互作用。

在以前的工作中，我们在鱿鱼神经元的突触前末端鉴定了一种RNA结合蛋白，该蛋白可能与局部mRNA加工有关。有证据表明，这种称为p65的强碱性蛋白是SDS稳定的二聚体蛋白，由〜37 kDa hnRNPA / B样亚基组成。p65在突触前区域中的功能尚不清楚。在这项工作中，我们显示p65及其亚基p37集中在突触小体中的RNA富集区域中。我们对重组蛋白进行了体外结合研究，并显示了其在鱿鱼突触前末端选择性结合肌动蛋白mRNA的倾向。使用裂解的突触体的生化分析表明，RNA完整性可能会影响p65和p37的功能。oligo（dT）下拉质谱分析表明乌贼hnRNPA1，hnRNPA1样2，