Characterization of a cDNA clone encoding molluscan insulin-related peptide II of Lymnaea stagnalis.
A cDNA clone encoding molluscan insulin-related peptide (MIP) II was isolated from a cDNA library of the central nervous system (CNS) of the freshwater snail, Lymnaea stagnalis, using a heterologous screening with a previously identified MIP cDNA (renamed MIP-I cDNA). The MIP-II cDNA encodes a preprohormone resembling the organization of preproinsulin, with a putative signal sequence, and A and B chains; however, in this case connected by two distinct C peptides, C alpha and C beta, instead of a single C peptide, a phenomenon which represents a new development in the prohormone organization of peptides belonging to the insulin superfamily. The A and B chains of MIP II and I differ remarkably in primary structure; in contrast, the C alpha peptide domains are fully identical. MIP II has only limited sequence similarity with insulins and related peptides. Both MIP II and I exhibit structural features, which make them a unique class of the insulin superfamily. The MIP I and II genes are expressed in a single type of neuron: the growth-controlling neuroendocrine light green cells of the Lymnaea CNS.
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Department of Biology, Vrije Universiteit, Amsterdam, The Netherlands.
Geraerts
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PM
Meester
I
I
van Heerikhuizen
H
H
Joosse
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J
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D005724:Ganglia / Q000166:cytology / Q000502:physiology; D015723:Gene Library; D008195:Lymnaea / Q000235:genetics*; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D015345:Oligonucleotide Probes; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid
D009479:Neuropeptides; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; C063879:insulin-related neuropeptide; D004247:DNA