The nuclear matrix from rat liver is capable of phosphorylating exogenous tyrosine-containing substrates.
The nuclear matrix isolated from rat liver phosphorylated exogenous tyrosine-containing substrates angiotensin II and synthetic polymer (Glu, Tyr; 4:1). The phosphorylation reaction was dependent on Mn2+ or Mg2+, but the former was the preferred ion. Km values for poly(Glu,Tyr; 4:1) and ATP were 0.2 mM and 4 microM, respectively. Angiotensin II showed a lower affinity for the kinase than poly(Glu,Tyr; 4:1). The isoflavone genistein, a specific inhibitor for tyrosine phosphorylation, inhibited the tyrosine kinase activity in the nuclear matrix.
Teraoka
H
H
Department of Pathological Biochemistry, Tokyo Medical and Dental University, Japan.
Ohmura
Y
Y
Tsukada
K
K
D000255:Adenosine Triphosphate / Q000032:analysis; D000596:Amino Acids / Q000032:analysis; D000804:Angiotensin II / Q000378:metabolism*; D000818:Animals; D002384:Catalysis; D002467:Cell Nucleus / Q000201:enzymology* / Q000648:ultrastructure; D019833:Genistein; D007529:Isoflavones / Q000494:pharmacology; D007700:Kinetics; D008099:Liver / Q000648:ultrastructure; D008274:Magnesium / Q000378:metabolism; D008345:Manganese / Q000378:metabolism; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D014443:Tyrosine / Q000378:metabolism
D000596:Amino Acids; D007529:Isoflavones; D000804:Angiotensin II; D014443:Tyrosine; D008345:Manganese; D000255:Adenosine Triphosphate; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D008274:Magnesium