Mouse Erk-1 gene product is a serine/threonine protein kinase that has the potential to phosphorylate tyrosine.
Bacterial expression of mouse gene Erk-1 yielded an active kinase with the same substrate specificity shown for ERK1 protein purified from rat cells. Although rat gene ERK1 is believed to encode a serine/threonine kinase based on sequence data and known ERK1 substrate phosphorylation sites, bacterially-produced mouse Erk-1 (bt-Erk-1) autophosphorylated on tyrosine in addition to serine and threonine residues. The bt-Erk-1 protein also had the capacity to reactivate the ribosomal protein S6 kinase (S6KII). Furthermore, treatment of bt-Erk-1 with either serine/threonine-specific phosphatase 2A or tyrosine-specific phosphatase 1B significantly decreased its kinase activity. These findings predict that autophosphorylation may play an important role in Erk-1/ERK1 regulation.
Crews
C M
CM
Department of Cellular and Developmental Biology, Harvard University, Cambridge, MA 02138.
Alessandrini
A A
AA
Erikson
R L
RL
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D003001:Cloning, Molecular; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D004676:Myelin Basic Protein / Q000378:metabolism; D009841:Oligonucleotides / Q000737:chemistry; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D010750:Phosphoproteins / Q000276:immunology / Q000502:physiology*; D019000:Phosphotyrosine; D016133:Polymerase Chain Reaction; D011494:Protein Kinases / Q000378:metabolism / Q000502:physiology*; D054648:Protein Phosphatase 2; D017346:Protein Serine-Threonine Kinases; D011994:Recombinant Proteins / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
D004676:Myelin Basic Protein; D009841:Oligonucleotides; D010750:Phosphoproteins; D011994:Recombinant Proteins; D019000:Phosphotyrosine; D014443:Tyrosine; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2