Identification of four trp1 gene variants murine pancreatic beta-cells.
Insulin secretion is stimulated by glucose, hormones and neurotransmitters. Both activation of a non-selective cation current and activation of a Ca2+ current in response to depletion of intracellular Ca2+ stores have been suggested to play a role in this stimulation. The properties of these currents resemble those reported for the Drosophila genes trp and trpl. Using the reverse transcription polymerase chain reaction and Northern blot analysis we found that of the six mammalian trp-related genes (trp1-6), only trp1 was expressed at high levels in the mouse insulinoma cell line MIN6. We cloned the murine homologue of human trp1 from MIN6 cells and identified four variants (alpha, beta, gamma and delta), generated by alternative splicing near the N-terminus of the protein. In vitro translation showed that only the alpha and beta splice variants are efficiently expressed. The beta variant is the dominant form in MIN6 cells (and probably in mouse pancreatic islets), whereas the alpha variant is the major type in the mouse brain. The beta variant showed 99% identity to the human homologue at the amino acid level.
Sakura
H
H
University Laboratory of Physiology, Oxford, UK.
Ashcroft
F M
FM
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015220:Calcium Channels / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D002460:Cell Line; D003001:Cloning, Molecular; D017931:DNA Primers; D004330:Drosophila; D029721:Drosophila Proteins; D015723:Gene Library; D014644:Genetic Variation; D006801:Humans; D019476:Insect Proteins / Q000737:chemistry; D007340:Insulinoma / Q000378:metabolism; D007515:Islets of Langerhans / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010190:Pancreatic Neoplasms / Q000378:metabolism; D016133:Polymerase Chain Reaction; D014176:Protein Biosynthesis; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D050052:TRPC Cation Channels; D014162:Transfection; D050051:Transient Receptor Potential Channels
D015220:Calcium Channels; D017931:DNA Primers; D029721:Drosophila Proteins; D019476:Insect Proteins; D011994:Recombinant Proteins; D050052:TRPC Cation Channels; D050051:Transient Receptor Potential Channels; C096351:transient receptor potential cation channel, subfamily C, member 1; C063169:trp protein, Drosophila