No significant tyrosine phosphorylation of muscle fatty acid-binding protein.
As suggested by the work on adipocyte fatty acid-binding protein (FABP), other FABPs with a tyrosine kinase consensus sequence could possibly be phosphorylated by the insulin receptor tyrosine kinase. Upon stimulation with insulin, recombinant human muscle fatty acid-binding protein (M-FABP) was phosphorylated in vitro by the insulin receptor tyrosine kinase only to a slight extent (< 0.1%). Rat soleus muscle shows at incubation autophosphorylation of insulin receptors but not phosphorylation of M-FABP after insulin stimulation. Vanadate and phenylarsine oxide had no effect on the extent of phosphorylation of M-FABP in vitro and in soleus muscle. Our results do not indicate that tyrosine phosphorylation of M-FABP is an important physiological phenomenon.
Prinsen
C F
CF
Department of Biochemistry, University of Nijmegen, The Netherlands.
Werten
P J
PJ
Maassen
J A
JA
Veerkamp
J H
JH
D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry*; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D006801:Humans; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology; D008297:Male; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000378:metabolism*; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D011972:Receptor, Insulin / Q000302:isolation & purification / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry; D025521:Tumor Suppressor Proteins; D014443:Tyrosine / Q000737:chemistry / Q000378:metabolism*
D002352:Carrier Proteins; C107608:FABP7 protein, human; C490174:Fabp7 protein, rat; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D007328:Insulin; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D011994:Recombinant Proteins; D025521:Tumor Suppressor Proteins; D014443:Tyrosine; D011972:Receptor, Insulin