DARPP-32 (dopamine and cAMP-regulated phosphoprotein, M(r) 32,000) is a membrane protein in the bovine parathyroid.
A distinct form of DARPP-32, a protein phosphatase-1 inhibitor, has been identified in bovine calf parathyroid glands. Immunoblot analysis of parathyroid tissue revealed a 32 kDa protein present predominantly in a particulate fraction; it remained particulate after treatment with 1.0 M NaCl or 0.1 M Na2CO3. Metabolic labeling of parathyroid cells with mevalonolactone demonstrated that DARPP-32 is isoprenylated. Immunocytochemical localization studies demonstrated that DARPP-32 is present in vesicles throughout the cytoplasm of parathyroid cells, and that protein phosphatase-1 gamma is concentrated in the region of the plasma membrane. Thus, in contrast to the predominately soluble form of DARPP-32 that has been characterized in selected areas of the central nervous system, the parathyroid form is tightly associated with intracellular membranes.
Matovcik
L M
LM
Department of Surgery, West Haven Department of Veterans Affairs Medical Center, CT 06516, USA.
Hemmings
H C
HC
Kinder
B K
BK
D000818:Animals; D001923:Brain Chemistry; D002417:Cattle; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D005455:Fluorescent Antibody Technique; D007527:Isoenzymes / Q000302:isolation & purification; D008565:Membrane Proteins / Q000302:isolation & purification*; D008566:Membranes / Q000737:chemistry / Q000276:immunology / Q000648:ultrastructure; D016253:Microscopy, Immunoelectron; D009419:Nerve Tissue Proteins / Q000276:immunology / Q000302:isolation & purification*; D010280:Parathyroid Glands / Q000737:chemistry*; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors* / Q000302:isolation & purification; D010750:Phosphoproteins / Q000302:isolation & purification*; D054645:Protein Phosphatase 1; D017368:Protein Prenylation; D013347:Subcellular Fractions / Q000737:chemistry / Q000276:immunology / Q000648:ultrastructure; D014018:Tissue Distribution
D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D007527:Isoenzymes; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D010750:Phosphoproteins; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1