ERKs: a family of protein-serine/threonine kinases that are activated and tyrosine phosphorylated in response to insulin and NGF

• Published in: Cell Vol. 65; no. 4; p. 663
• Main Authors: Boulton, Teri G, Nye, Steven H, Robbins, David J, Ip, Nancy Y, Radziejewska, Elizabeth, Morgenbesser, Sharon D, DePinho, Ronald A, Panayotatos, Nikos, Cobb, Melanie H, Yancopoulos, George D
• Format: Journal Article
• Language: English
• Published: United States 17-05-1991
• Subjects: Amino Acid Sequence; Animals; Astrocytes - enzymology; Base Sequence; Cell Line; Cells, Cultured; Cloning, Molecular; Enzyme Activation; Hippocampus - enzymology; Humans; Insulin - pharmacology; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinase 6; Mitogen-Activated Protein Kinases; Molecular Sequence Data; Nerve Growth Factors - pharmacology; Organ Specificity; Phosphorylation; Protein Kinases - genetics; Protein Kinases - isolation & purification; Protein Kinases - metabolism; Pseudogenes; Rats; Recombinant Proteins - metabolism; Sequence Homology, Nucleic Acid; Teratoma; Tyrosine
• ISSN: 0092-8674
• DOI: 10.1016/0092-8674(91)90098-J

We recently described the purification and cloning of extracellular signal-regulated kinase 1 (ERK1), which appears to play a pivotal role in converting tyrosine phosphorylation into the serine/threonine phosphorylations that regulate downstream events. We now describe cloning and characterization of two ERK1-related kinases, ERK2 and ERK3, and provide evidence suggesting that there are additional ERK family members. At least two of the ERKs are activated in response to growth factors; their activations correlate with tyrosine phophorylation, but also depend on additional modifications. Transcripts corresponding to the three cloned ERKs are distinctly regulated both in vivo and in a differentiating cell line. Thus, this family of kinases may serve as intermediates that depend on tyrosine phosphorylation to activate serine/threonine phosphorylation cascades. Individual family members may mediate responses in different developmental stages, in different cell types, or following exposure to different extracellular signals.