GTPbl

GTPbl, also known as Guanine Nucleotide Exchange Factor for p21-activated Kinase 1 (Pak1), is a protein that plays a crucial role in various cellular processes, including cell migration, proliferation, and survival. It is a member of the Rho family of small GTPases, which are molecular switches that regulate numerous cellular functions by cycling between an active GTP-bound state and an inactive GDP-bound state.

GTPbl is activated by upstream signaling molecules, such as integrins and growth factor receptors, which trigger the exchange of GDP for GTP on the GTPbl protein. This activation leads to the formation of GTPbl-GTP, which in turn activates downstream effectors, including Pak1. Pak1 is a serine/threonine kinase that phosphorylates various substrates, including actin and myosin, to regulate actin dynamics and cell motility.

GTPbl is also involved in cell proliferation and survival. It has been shown to regulate the activity of the transcription factor NF-κB, which is a key regulator of inflammation and cell survival. GTPbl can activate NF-κB by inhibiting the activity of IκB, a protein that normally sequesters NF-κB in the cytoplasm.

GTPbl is expressed in a wide range of tissues and cell types, and its expression and activity are regulated by various signaling pathways. Dysregulation of GTPbl has been implicated in several diseases, including cancer, inflammation, and cardiovascular disease. Therefore, understanding the molecular mechanisms underlying GTPbl regulation and function is of great interest for the development of new therapeutic strategies.