A novel Leydig cell cDNA-derived protein is a relaxin-like factor.
According to Burkhardt et al. (Burkhardt, E., Adham, I. M., Brosig, B., Gastmann, A., Mattei, M. G., and Engel, W. (1994) Genomics 20, 13-19) Leydig cells contain the message for a protein of the insulin/relaxin family which was named Leydig cell insulin-like protein (LEY I-L). We have synthesized the human LEY I-L according to the amino acid sequence deduced from the published cDNA structure and obtained preliminary results concerning its potential target organs and its biological activity. Leydig cell insulin-like protein binds specifically to crude membrane preparations of mouse uterus and brain and shows cross-reactivity with the relaxin receptor, but not the insulin receptor. On the basis of these observations, together with the results of earlier structure-function considerations, we suggest that the new protein is a relaxin-like factor. By itself the new factor shows no obvious effect, but when given together with relaxin it significantly enhances relaxin-mediated widening of the mouse symphysis pubis.
Büllesbach
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Department of Biochemistry and Molecular Biology Medical University of South Carolina, Charleston.
Schwabe
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D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001681:Biological Assay; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D006801:Humans; D007328:Insulin; D007985:Leydig Cells; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D011485:Protein Binding; D011506:Proteins / Q000235:genetics*; D043562:Receptors, G-Protein-Coupled; D018000:Receptors, Peptide / Q000378:metabolism; D012065:Relaxin / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D013045:Species Specificity; D013552:Swine; D014018:Tissue Distribution
D000596:Amino Acids; D018076:DNA, Complementary; D007328:Insulin; C084797:Leydig insulin-like protein; D011506:Proteins; D043562:Receptors, G-Protein-Coupled; D018000:Receptors, Peptide; C033395:relaxin receptors; D012065:Relaxin