P27361, P28482

The ERK proteins, which include ERK 1 and ERK 2, play a crucial role in mediating the activation of signal transduction pathways triggered by growth factors, hormones, and neurotransmitters. These proteins are located in the cytoplasm and translocate to the nucleus upon activation, where they regulate gene expression and influence cell proliferation, differentiation, and survival. The dual phosphorylation of ERK at specific threonine and tyrosine residues is essential for their full enzymatic activation, allowing them to phosphorylate downstream targets on serine and threonine residues. Key upstream regulators of ERK include MAP kinase kinase (MEK), MEK kinase, and Raf-1, which are vital for the proper functioning of the MAPK signaling cascade.