Smit A B, Spijker S, Van Minnen J, Burke J F, De Winter F, Van Elk R, Geraerts W P
Department of Experimental Zoology, Vrije Universiteit, Amsterdam, Netherlands.
Neuroscience. 1996 Jan;70(2):589-96. doi: 10.1016/0306-4522(95)00378-9.
A complementary DNA clone encoding molluscan insulin-related peptide VII was identified from a complementary DNA library of the cerebral ganglia of the CNS of the freshwater snail, Lymnaea stagnalis. The novel molluscan insulin-related peptide VII complementary DNA encodes a preprohormone resembling the organization of preproinsulin, with a putative signal sequence, and an A and B chain, and is connected by an unusual long C peptide. The A and B chains, as well as the C peptide of molluscan insulin-related peptide VII, differ remarkably in primary structure with the previously identified molluscan insulin-related peptides. The C peptide of molluscan insulin-related peptide VII shares no significant sequence identity with counterparts in other molluscan insulin-related peptides. Both molluscan insulin-related peptide VII and the other molluscan insulin-related peptides exhibit structural features which make them a unique class of the insulin superfamily. Molluscan insulin-related peptide VII complementary DNA was shown to hybridize in situ with messenger RNA present in the cerebral light green cells, neuroendocrine cells that control growth and that have previously been shown to produce molluscan insulin-related peptides I-III and V. Uniquely, the molluscan insulin-related peptide VII gene is also expressed in neurons that may form part of the feeding circuitry in Lymnaea, indicating that it may function as a neurotransmitter/neuromodulator.
从淡水螺椎实螺中枢神经系统（CNS）脑神经节的互补DNA文库中鉴定出一个编码软体动物胰岛素相关肽VII的互补DNA克隆。这种新型的软体动物胰岛素相关肽VII互补DNA编码一种前激素原，其结构类似于胰岛素原，具有一个假定的信号序列、一条A链和一条B链，并通过一条异常长的C肽连接。软体动物胰岛素相关肽VII的A链、B链以及C肽在一级结构上与先前鉴定的软体动物胰岛素相关肽有显著差异。软体动物胰岛素相关肽VII的C肽与其他软体动物胰岛素相关肽的对应肽段在序列上没有明显的一致性。软体动物胰岛素相关肽VII和其他软体动物胰岛素相关肽都具有一些结构特征，这使它们成为胰岛素超家族中的独特一类。研究表明，软体动物胰岛素相关肽VII互补DNA能与存在于脑浅绿色细胞中的信使RNA进行原位杂交，这些神经内分泌细胞控制生长，并且先前已被证明能产生软体动物胰岛素相关肽I - III和V。独特的是，软体动物胰岛素相关肽VII基因也在可能构成椎实螺进食回路一部分的神经元中表达，这表明它可能作为一种神经递质/神经调质发挥作用。
