plexin-B1 Activators

Plexin-B1 is a transmembrane receptor protein that belongs to the plexin family, which serves as a critical regulator of cellular functions such as cell migration, axon guidance, angiogenesis, and immune responses. As a member of the semaphorin receptor family, plexin-B1 primarily interacts with its ligands, the class IV semaphorins, particularly semaphorin 4D (Sema4D). Through these interactions, plexin-B1 mediates repulsive guidance cues during neuronal development and plays essential roles in other cellular processes, including regulation of cell adhesion, cytoskeletal rearrangement, and signaling pathway activation.

Activation of plexin-B1 occurs upon binding of its ligands, such as Sema4D, which triggers a cascade of intracellular signaling events leading to various cellular responses. Upon ligand binding, plexin-B1 undergoes conformational changes and forms complexes with its co-receptors, such as neuropilins or integrins, depending on the cellular context. These interactions facilitate the activation of downstream signaling pathways, including Rho family GTPases such as RhoA, Rac1, and Cdc42, as well as downstream effectors such as p21-activated kinase (PAK) and Src family kinases. Activation of these signaling cascades leads to cytoskeletal rearrangements, changes in cell morphology, and alterations in cell motility and migration. Additionally, plexin-B1 activation can modulate cellular adhesion through interactions with integrins and other cell adhesion molecules, further influencing cell behavior and function. Overall, plexin-B1 activation orchestrates a complex array of cellular responses that are crucial for various physiological and developmental processes in multicellular organisms.