What process is altered by the kinase cascade initiated by INSR?

The kinase cascade initiated by the insulin receptor (INSR) primarily affects gene expression, which is crucial in cellular responses to insulin. When insulin binds to its receptor, it activates a series of downstream signaling cascades, most notably through the phosphoinositide 3-kinase (PI3K)/Akt pathway. This cascade results in the phosphorylation of various substrates that ultimately lead to changes in gene expression.

Insulin plays a significant role in regulating glucose metabolism, lipid synthesis, and protein metabolism by modulating the transcription of specific genes. For instance, it promotes the expression of genes responsible for glucose uptake (such as GLUT4) and lipogenesis while inhibiting those involved in gluconeogenesis (like G6Pase). Thus, the insulin signaling pathway has a direct influence on gene expression, shaping various metabolic processes.

While the other processes mentioned — glycolysis, lipid metabolism, and protein synthesis — are influenced by insulin, they are more downstream effects of the changes in gene expression rather than processes that the kinase cascade directly alters initially. The signaling pathway’s primary role is to transduce the insulin signal that leads to alterations in gene expression, ultimately affecting those other metabolic pathways as a result.