Protein synthesis in vitro by mantle tissue of the land snail Otala lactea: possible insulin-like peptide function

Abstract

Mantle-collar tissue from adult land snails Otala lactea continuously incorporated labelled amino acids over a 72-h period of incubation in modified culture medium. Acid-saline extract of cerebral ganglia stimulated protein synthesis by the mantle-collar tissue in vitro. This effect was dose-dependent, with the minimum and maximum doses at 0.5 and 2 cerebral ganglion equivalents, respectively. The protein synthesis-stimulating factor(s) from the cerebral ganglia appeared to be proteinaceous and hydrophobic in nature. The cerebral ganglion extract was fractionated by means of a size-exclusion HPLC column. The biological activity was induced by three fractions with estimated molecular masses of 0.82, 1.88, and 4.33 kilodaltons (kDa). Porcine insulin antiserum abolished the activity of the 4.33- and 1.88-kDa fractions but had no significant effect on the activity of the 0.82-kDa fraction. The results suggest the existence in the cerebral ganglia of more than one factor with protein synthesis-stimulating activity. One of these factors could be related to mammalian insulin. Porcine insulin, however, had no significant effect on protein synthesis by the mantle collar in vitro.

Identification and Characterization of Neuropeptides by Transcriptome and Proteome Analyses in a Bivalve Mollusc Patinopecten yessoensis

“…The high expression of insulin-like peptide 3 and LRYamide indicates these two genes may be involved in the regulation of shell growth. Previous studies of insulin-like peptides in snail and oyster support our assumption: insulin-like peptides can stimulate protein synthesis in mantle edge cells, and regulate the growth of the mantle edge and shell ( Abdraba and Saleuddin, 2000 ; Gricourt et al, 2003 ). The other neuropeptide LRYamide is newly identified, therefore remains to be studied.…”