Many Receptors of the Immune System Activate Protein Kinases as a Mechanism

question 40

Essay

Many receptors of the immune system activate protein kinases as a mechanism of initiating signaling. For antigen receptors on lymphocytes, ligand binding induces receptor clustering, and the enzymes activated are protein tyrosine kinases. Based on this mechanism, predict the outcome of expressing a mutant form of the receptor-associated tyrosine kinase in cells that still express the wild-type version of this enzyme, and explain your reasoning. This mutant is unable to bind ATP and therefore is catalytically inactive; assume the mutant and wild-type forms of the kinase are expressed in equimolar amounts.

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Definitions:

Post-Translational

Refers to the changes a protein may undergo after translation, including folding, cutting, and addition of chemical groups, which are crucial for its final function.

Knockout

An experiment in which a gene is deliberately inactivated in a living organism; also, an organism that carries a knocked-out gene.

Inactivate

To render something inactive or no longer in effect, often used in contexts such as deactivating enzymes, genes, or pharmaceuticals.

Experiments

Controlled procedures carried out to investigate the effect of a variable by providing precise data and observations.