Regulation of mitogen activated protein kinases through heterotrimeric G proteins

Abstract

Heterotrimeric G proteins are known as G proteins, consist of α, β, and γ subunits. G protein mediated signaling is employed by virtually all cells in the mammalian organism and is centrally involved in diverse physiological functions such as perception of sensory information, modulation of synaptic transmission, hormone release and actions, regulation of cell contraction and migration, or cell growth and differentiation. The amino acid identity of the α subunits has been used as basis for the classification of G proteins into four families Gs, Gi, Gq, and G12. G proteins stimulate distinct downstream effectors including enzymes, ion channels and small GTPase, thus regulating multiple signaling pathways including those involved in the activation of mitogen-activated protein kinase pathways. Mitogen-activated protein kinases are a family that constitute signaling pathways involved in processes that control gene expression, cell division, cell survival, apoptosis, metabolism, differentiation and motility. The mitogen-activated protein kinase family includes ERK1/2, c-Jun N-terminal kinazlar 1, 2 ve 3, p38MAPK a, b, g, and d, and ERK5 as classical mitogen-activated protein kinases, and ERK3, ERK4 NLK, and ERK7 as atypical mitogen-activated protein kinases. Each of mitogen-activated protein kinase pathways consists of three distinct kinases, namely an upstream respectively; mitogen-activated protein kinase kinase kinase , mitogen-activated protein kinase kinase and mitogen-activated protein kinase