Question

Many mutations in receptor kinases that lead to cancer allow the receptor to dimerize and become activated. True or False

Answer 1

The correct answer is: True.

Explanation:

• Signal transduction pathway can be defined as the mechanism by which a stimulus from the external environment of a cell is transmitted to the interior of the cell so that the cell can develop appropriate response to it.
• A typical signalling pathway involves the following steps,

1. Binding of the signal molecule to the receptor.
2. Activation of the receptor protein and downstream signalling molecules.
3. Activation or release of secondary messengers inside the cells.
4. Activation of kinases and other enzymes inside the cells.
5. Appropriate response given by the cells, in form of change in structure or function.

• In some signalling pathways, the binding of signal molecule to the receptor kinases causes the dimerization of the receptor molecules followed by the trans-auto phosphorylation of the receptor molecules.
• The phosphorylation of the receptor molecule causes it to remain constitutively active and  pass signal into the cell continuously.
• In certain cancers, often these receptor kinases get mutated and dimerize spontaneously even in the absence of the signalling molecule, thereby causing uncontrolled activation of the particular signalling pathway in the cell resulting in cancer development.