Involvement of type 2C phosphatase in the dephosphorylation of 26 kDa phosphoprotein in rat parotid acinar cells.
Phosphorylation of three particulate proteins with molecular masses of 34, 26, and 22 kDa was stimulated in the presence of cyclic AMP/3-isobutyl-1-methylxanthine in saponin-permeabilized rat parotid acinar cells. When the particulate fraction isolated from the cells labeled with [gamma-32p]ATP was incubated at 30 degrees C, dephosphorylation of the 26 kDa phosphoprotein occurred in the presence of Mg2+ or Mn2+. Okadaic acid had no effect on the Mg(2+)-dependent dephosphorylation of the 26 kDa phosphoprotein. Addition of the recombinant type 2C phosphatase, Mg(2+)-dependent and okadaic acid-insensitive phosphatase, caused a remarkable dephosphorylation of the 26 kDa phosphoprotein. These observations strongly suggest type 2C phosphatase is involved in the dephosphorylation of the 26 kDa phosphoprotein.
Yokoyama
N
N
Department of Physiology, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
Hara-Yokoyama
M
M
Kobayashi
T
T
Tamura
S
S
Furuyama
S
S
Sugiya
H
H
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D002463:Cell Membrane Permeability; D000242:Cyclic AMP / Q000378:metabolism / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D004988:Ethers, Cyclic / Q000494:pharmacology; D066298:In Vitro Techniques; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D008274:Magnesium / Q000494:pharmacology; D008970:Molecular Weight; D019319:Okadaic Acid; D010306:Parotid Gland / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010750:Phosphoproteins / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism
D004988:Ethers, Cyclic; D007527:Isoenzymes; D010750:Phosphoproteins; D011994:Recombinant Proteins; D019319:Okadaic Acid; D004533:Egtazic Acid; D004492:Edetic Acid; D000242:Cyclic AMP; D017027:Protein Tyrosine Phosphatases; D008274:Magnesium; D015056:1-Methyl-3-isobutylxanthine