title: Nucleobindin-1 encodes a nesfatin-1-like peptide that stimulates insulin secretion.
abstract: Nesfatin-1 (82 amino acid) is an anorexigenic and insulinotropic peptide encoded in a secreted precursor, nucleobindin-2 (NUCB2). Nucleobindin-1 (NUCB1) is a protein with very high sequence similarity to NUCB2. We hypothesized that a nesfatin-1 like peptide (NLP) is encoded in NUCB1, and this peptide is biologically active. In silico analysis found a signal peptide cleavage site at position 25 (Arginine) and 26 (Valine) preceding the NLP region in NUCB1 sequence, and potential proprotein convertase cleavage sites at Lys-Arg (KR), forming a 77 amino acid NLP. RT-PCR studies found NUCB1 mRNA in both pancreas and MIN6 cells. NUCB1-like immunoreactivity was detected in mouse insulinoma (MIN6) cells, and pancreatic islet beta cells of mice. In order to determine the biological activity of NLP, MIN6 cells were incubated with synthetic rat NLP. NLP (10nM and 100nM) upregulated preproinsulin mRNA expression and insulin secretion at 1h post-incubation. In identical experiments using MIN6 cells, a scrambled peptide based on the NLP sequence did not elicit any effects on preproinsulin mRNA expression or insulin secretion. From this result, it is clear that an intact NLP sequence is required for its biological activity. NLP appears as another endogenous insulinotropic peptide encoded in NUCB1.
authors.affiliation: Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B4, Canada.
authors.forename: Naresh
authors.initials: N
authors.lastname: Ramesh
authors.affiliation: Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B4, Canada.
authors.forename: Haneesha
authors.initials: H
authors.lastname: Mohan
authors.affiliation: Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B4, Canada. Electronic address: suraj.unniappan@usask.ca.
authors.forename: Suraj
authors.initials: S
authors.lastname: Unniappan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects*; D007124:Immunoenzyme Techniques; D007328:Insulin / Q000235:genetics / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D007340:Insulinoma / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D000080866:Nucleobindins; D010446:Peptide Fragments / Q000494:pharmacology*; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
chemical_list: D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D007328:Insulin; D009419:Nerve Tissue Proteins; C000630651:Nucb1 protein, mouse; C000630652:Nucb1 protein, rat; D000080866:Nucleobindins; D010446:Peptide Fragments; D011498:Protein Precursors; D012333:RNA, Messenger; C013737:preproinsulin
keywords: Insulin; Islets; MIN6; Nesfatin-1; Nucleobindin; Pancreas