A phosphorylation cascade is a sequence of signaling pathway events where one enzyme phosphorylates another, causing a chain reaction leading to the phosphorylation of thousands of proteins. This can be seen in signal transduction of hormone messages.
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A signaling pathway begins at the cell surface where a hormone or protein binds to a receptor at the Extracellular matrix. The interactions between the molecule and receptor cause a Conformational change at the receptor, which activates multiple enzymes or proteins. These enzymes activate secondary messengers, which leads to the phosphorylation of thousands of proteins. The end product of a Phosphorylation cascade is the changes occurring inside the cell.
One best example that explains this phenomenon is mitogen-activated protein (MAP) kinase or ERK kinase.[1] MAP kinase not only plays an important function during growth of cell in the M phase phosphorylation cascade but also plays an important role during the sequence of signaling pathway[2]. In order to regulate its functions so it does not cause chaos, it can only be active when both tyrosine and threonine/serine residues are phosphorylated.[3]
References
- ^ Denhardt, David T. (1996-09-15). "Signal-transducing protein phosphorylation cascades mediated by Ras/Rho proteins in the mammalian cell: the potential for multiplex signalling". Biochemical Journal. 318 (3): 729–747. doi:10.1042/bj3180729. ISSN 0264-6021. PMC 1217680. PMID 8836113.
- ^ Man, The Protein. "Protein Kinases and Phosphatases: drivers of phosphorylation and dephosphorylation". info.gbiosciences.com. Retrieved 2020-04-28.
- ^ Matsuda, S.; Kosako, H.; Takenaka, K.; Moriyama, K.; Sakai, H.; Akiyama, T.; Gotoh, Y.; Nishida, E. (1 March 1992). "Xenopus MAP kinase activator: identification and function as a key intermediate in the phosphorylation cascade". The EMBO Journal. 11 (3): 973–982. doi:10.1002/j.1460-2075.1992.tb05136.x. ISSN 0261-4189. PMC 556538. PMID 1312468.
- Freeman, Scott; et al. (2005). "Index I" Biological Science Vol. 2. Pearson Education, Inc.