Segregation of two glutaminase isoforms in islets of Langerhans.
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.
Baglietto-Vargas
David
D
Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain.
López-Téllez
Juan F
JF
Moreno-González
Inés
I
Gutiérrez
Antonia
A
Aledo
J Carlos
JC
D000818:Animals; D005972:Glutaminase / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism; D007668:Kidney / Q000201:enzymology; D007801:Langerhans Cells / Q000201:enzymology*; D008099:Liver / Q000201:enzymology; D008297:Male; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley
D007527:Isoenzymes; D005972:Glutaminase