Linked Life Data

7760845

Source:http://linkedlifedata.com/resource/pubmed/id/7760845

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1995-6-26
pubmed:databankReference
pubmed:abstractText
Dihydropyridine-sensitive voltage-dependent calcium channels (VDCC) play a crucial role in insulin secretion. We recently have cloned a human alpha 1-subunit of the VDCC expressed in pancreatic beta-cells, designated CACN4. In this study we have isolated complementary DNAs encoding two forms of rat CACN4 (rCACN4A and rCACN4B) from a rat insulinoma RINm5F complementary DNA library. Rat CACN4A is a protein of 2203 amino acids and is the rat homolog of human CACN4, whereas rCACN4B lacks 535 amino acids in the carboxyl-terminal region, probably due to alternative splicing. We have found two additional variations, one in the intracellular loop between repeats I and II and the other in the extracellular region between the third and fourth segments of repeat IV. Reverse transcriptase-polymerase chain reaction analysis of rat pancreatic islet messenger RNA reveals that these variants are present in pancreatic islets. In addition, whole-cell voltage-clamp recordings of Chinese hamster ovary cells stably expressing the alpha 1-subunit (rCACN4A or rCACN4B) with or without the calcium channel beta 2-subunit show that coexpression of rCACN4A with the beta 2-subunit or rCACN4B with the beta 2-subunit elicits L-type VDCC currents, whereas expression of the alpha 1-subunit alone does not, indicating that CACN4 can associate functionally with the beta 2-subunit and that the beta-subunit is essential for functional expression of CACN4. These results suggest that there are various subtypes of CACN4 expressed in pancreatic beta-cells, and that both rCACN4A and rCACN4B can function as VDCC. Furthermore, the present study suggests that the expression of the beta-subunit as well as the alpha 1-subunit may participate in the regulation of insulin secretion.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0888-8809
pubmed:author
pubmed:issnType
Print
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
121-30
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:7760845-Amino Acid Sequence, pubmed-meshheading:7760845-Animals, pubmed-meshheading:7760845-Base Sequence, pubmed-meshheading:7760845-Calcium, pubmed-meshheading:7760845-Calcium Channels, pubmed-meshheading:7760845-Calcium Channels, L-Type, pubmed-meshheading:7760845-Cloning, Molecular, pubmed-meshheading:7760845-DNA, Complementary, pubmed-meshheading:7760845-Humans, pubmed-meshheading:7760845-Insulinoma, pubmed-meshheading:7760845-Ion Channel Gating, pubmed-meshheading:7760845-Islets of Langerhans, pubmed-meshheading:7760845-Molecular Sequence Data, pubmed-meshheading:7760845-Muscle Proteins, pubmed-meshheading:7760845-Pancreatic Neoplasms, pubmed-meshheading:7760845-Patch-Clamp Techniques, pubmed-meshheading:7760845-Polymerase Chain Reaction, pubmed-meshheading:7760845-RNA, Messenger, pubmed-meshheading:7760845-RNA Splicing, pubmed-meshheading:7760845-Rats, pubmed-meshheading:7760845-Recombinant Fusion Proteins, pubmed-meshheading:7760845-Sequence Alignment, pubmed-meshheading:7760845-Sequence Homology, Amino Acid, pubmed-meshheading:7760845-Species Specificity, pubmed-meshheading:7760845-Tumor Cells, Cultured
pubmed:year
1995
pubmed:articleTitle
Molecular diversity and functional characterization of voltage-dependent calcium channels (CACN4) expressed in pancreatic beta-cells.
pubmed:affiliation
Department of Metabolism and Clinical Nutrition Kyoto University Faculty of Medicine, Japan.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't