Segregation of two glutaminase isoforms in islets of Langerhans

Biochem J. 2004 Jul 15;381(Pt 2):483-7. doi: 10.1042/BJ20040523.

Abstract

Despite the importance of glutamatergic signalling in the co-ordination of hormone secretion, the identity of the enzyme for the production of glutamate in beta-cells is still unresolved. We have found that the endocrine pancreas co-expresses two isoforms of GA (glutaminase), denoted as kidney-type (KGA) and liver-type (LGA), with a complementary cellular pattern of expression. Whereas KGA was mainly present in alpha-cells, LGA was very abundant in beta-cells. This spatial segregation may have important functional implications, facilitating a differential regulation of glutamate production in insulin- and glucagon-secreting cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Glutaminase / metabolism*
  • Isoenzymes / metabolism
  • Kidney / enzymology
  • Langerhans Cells / enzymology*
  • Liver / enzymology
  • Male
  • Rabbits
  • Rats
  • Rats, Sprague-Dawley

Substances

  • Isoenzymes
  • Glutaminase