to investigate whether s6 phosphorylation in this system was a consequence of the action of the ab-mulv tyrosine-specific protein kinase , purified ab-mulv kinase made in escherichia coli was microinjected into xenopus oocytes and was observed to cause a 7- to 15-fold increase in the phosphorylation of s6 on serine residues .
C0033681
tyrosine-specific protein kinase
C0031727
kinase