Final answer:
The CI-MPR plays a role in modulating the availability of IGF-II by binding it, which in turn affects cellular processes such as protein expression, cellular metabolism, and cell division.
Step-by-step explanation:
The role of CI-MPR, also known as the IGF-II receptor, is essential in the regulation of cellular processes. While this question seems to refer to the insulin-like growth factor (IGF) receptor, it's important to distinguish that CI-MPR does have a role in regulating levels of IGF-II by binding it and thus modulating its availability to interact with its signaling receptor. Specifically, CI-MPR is involved in transporting enzymes and proteins, such as lysosomal enzymes, from the Golgi apparatus to lysosomes, and in some cases, it modulates signaling by binding growth factors like IGF-II.
It is involved in the transportation of proteins to lysosomes and regulation of growth factor levels, influencing cellular proliferation and apoptosis.
The effect of IGF-II on the cells is critical as it promotes cellular proliferation, enhances cellular uptake of amino acids, and inhibits apoptosis, which is largely mediated through the direct receptor called the IGF-I receptor. The IGF-I receptor, a tyrosine kinase, when activated by IGFs, initiates a cascade of intracellular signaling pathways, including the MAP-kinase and FAS-RAS pathways, which lead to changes in protein expression, cellular metabolism, and cell division. These processes are particularly important in tissues like skeletal muscle and cartilage, which are sensitive to growth-promoting effects of IGFs, as they stimulate these cells to utilize amino acids from the bloodstream to synthesize proteins, a mechanism crucial for growth and repair.