ERKs, also known as Extracellular Signal-Regulated Kinases, are a type of protein kinase that belong to the mitogen-activated protein kinase (MAPK) family. They play a crucial role in signal transduction pathways that regulate various cellular functions.
The ERK family consists of highly conserved serine/threonine kinases, and in mammals, ERK1 (or MAPK3) and ERK2 (or MAPK1) are the most studied isoforms. ERKs are activated in response to extracellular signals such as growth factors, hormones, cytokines, and stress stimuli. Once activated, these kinases phosphorylate a wide range of substrates including other kinases, transcription factors, and cytoskeletal proteins.
ERKs are involved in numerous cellular processes including cell growth, differentiation, proliferation, survival, and apoptosis. They are key regulators of gene expression and can modulate the activity of transcription factors through phosphorylation. ERK signaling pathway dysregulation has been implicated in various diseases including cancer, neurodegenerative disorders, cardiovascular diseases, and immune disorders.
In terms of structure, ERKs contain an N-terminal kinase domain, a regulatory phosphorylation site, and a C-terminal domain involved in protein-protein interactions. Activation of ERKs occurs through a cascade of phosphorylation events involving MAP kinase kinases (MEKs) that ultimately lead to ERK translocation to the nucleus, where they can phosphorylate target proteins to induce cellular responses.
In summary, ERKs are important signal transducers that play a crucial role in mediating cellular responses to extracellular cues, thereby regulating important physiological and pathological processes.
