Targeting of the 67-kDa isoform of glutamic acid decarboxylase to intracellular organelles is mediated by its interaction with the NH2- terminal region of the 65-kDa isoform of glutamic acid decarboxylase

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Standard

Targeting of the 67-kDa isoform of glutamic acid decarboxylase to intracellular organelles is mediated by its interaction with the NH2- terminal region of the 65-kDa isoform of glutamic acid decarboxylase. / Dirkx, R.; Thomas, A.; Li, L.; Lernmark, A.; Sherwin, R. S.; De Camilli, P.; Solimena, M.

I: Journal of Biological Chemistry, Vol. 270, Nr. 5, 01.01.1995, s. 2241-2246.

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Harvard

APA

CBE

MLA

Vancouver

Author

RIS

TY - JOUR

T1 - Targeting of the 67-kDa isoform of glutamic acid decarboxylase to intracellular organelles is mediated by its interaction with the NH2- terminal region of the 65-kDa isoform of glutamic acid decarboxylase

AU - Dirkx, R.

AU - Thomas, A.

AU - Li, L.

AU - Lernmark, A.

AU - Sherwin, R. S.

AU - De Camilli, P.

AU - Solimena, M.

PY - 1995/1/1

Y1 - 1995/1/1

N2 - The two isoforms of glutamic acid decarboxylase (GAD), GAD67 and GAD65, synthesize the neurotransmitter γ-aminobutyric acid in neurons and pancreatic β-cells. Previous studies suggest that GAD67 is a soluble cytosolic protein, whereas GAD65 is membrane-associated. Here we study the intracellular distribution of GAD67 in neurons, pancreatic β-cells, and fibroblasts transfected either with GAD65 and GAD67 together or with GAD67 alone. Neuronal GAD67 is partially recovered with GAD65 in membrane- containing pellet fractions and Triton X-114 detergent phases. The two proteins coimmunoprecipitate from extracts of brain and GAD65-GAD67 cotransfected fibroblasts, but not when extracts of GAD65 and GAD67 transfected fibroblasts were mixed and used as a stating material for immunoprecipitation. GAD67 is concentrated in the Gorgi complex region in GAD65-GAD67 cotransfected fibroblasts, but not in fibroblasts transfected with GAD67 alone. A pool of neuronal GAD67 colocalizes with GAD65 in the Golgi complex region and in many synapses. The two proteins also colocalize in the perinuclear region of some pancreatic ̄-cells. GAD67 interacts with the NH2-terminal region of GAD65, even in the absence of palmitoylation of this region of GAD65. Taken together, our results indicate that GAD65-GAD67 association occurs in vivo and is required for the targeting of GAD67 to membranes.

AB - The two isoforms of glutamic acid decarboxylase (GAD), GAD67 and GAD65, synthesize the neurotransmitter γ-aminobutyric acid in neurons and pancreatic β-cells. Previous studies suggest that GAD67 is a soluble cytosolic protein, whereas GAD65 is membrane-associated. Here we study the intracellular distribution of GAD67 in neurons, pancreatic β-cells, and fibroblasts transfected either with GAD65 and GAD67 together or with GAD67 alone. Neuronal GAD67 is partially recovered with GAD65 in membrane- containing pellet fractions and Triton X-114 detergent phases. The two proteins coimmunoprecipitate from extracts of brain and GAD65-GAD67 cotransfected fibroblasts, but not when extracts of GAD65 and GAD67 transfected fibroblasts were mixed and used as a stating material for immunoprecipitation. GAD67 is concentrated in the Gorgi complex region in GAD65-GAD67 cotransfected fibroblasts, but not in fibroblasts transfected with GAD67 alone. A pool of neuronal GAD67 colocalizes with GAD65 in the Golgi complex region and in many synapses. The two proteins also colocalize in the perinuclear region of some pancreatic ̄-cells. GAD67 interacts with the NH2-terminal region of GAD65, even in the absence of palmitoylation of this region of GAD65. Taken together, our results indicate that GAD65-GAD67 association occurs in vivo and is required for the targeting of GAD67 to membranes.

UR - http://www.scopus.com/inward/record.url?scp=0028929053&partnerID=8YFLogxK

U2 - 10.1074/jbc.270.5.2241

DO - 10.1074/jbc.270.5.2241

M3 - Article

C2 - 7836456

AN - SCOPUS:0028929053

VL - 270

SP - 2241

EP - 2246

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 1083-351X

IS - 5

ER -