RTK ( Receptor Tyrosine Kinases)
Many polypeptide growth factors, cytokines, and hormones have high-affinity cell surface receptors called receptor tyrosine kinases (RTKs). 58 of the 90 distinct tyrosine kinase genes found in the human genome encode proteins known as receptor tyrosine kinases. It has been demonstrated that receptor tyrosine kinases play a crucial role in the initiation and development of many different forms of cancer in addition to being important regulators of normal cellular activities. Mutations in receptor tyrosine kinases trigger a number of signalling cascades that have diverse impacts on the expression of proteins. Receptor tyrosine kinases are a subset of the wider family of protein tyrosine kinases that includes both non-receptor tyrosine kinases and receptor tyrosine kinase proteins that feature transmembrane domains.
There were 58 receptor tyrosine kinases (RTKs) identified in 2004, which were divided into 20 subfamilies. They are essential for many different cellular processes, such as differentiation, adhesion, motility, growth (via signalling neurotrophins), and death. RTKs are made up of an intracellular catalytic domain that can bind certain substrates and phosphorylate them, a transmembrane domain, and an extracellular domain that can bind a particular ligand. Numerous RTKs are implicated in the development of cancer, whether by chromosomal translocation, gene mutation, or simple overexpression. Every time, the outcome is a hyperactive kinase that provides the cancer cells with an abnormal, ligand-independent, uncontrolled growth stimulation.
Receptor Tyrosine Kinase Signaling
Cell signalling is a cell’s capacity to accept, process, and transmit messages to its surroundings and to itself. Cell signalling is a basic characteristic of all prokaryotic and eukaryotic cellular life. Extracellular signals (or signals that originate outside of a cell) can be physical agents such as mechanical pressure, electricity, temperature, light, or chemical signals (e.g., small molecules, peptides, or gas).