Question

Explain how the system of a single cell is supposed to function in a normal environment and how it is being affected by the item listed below. This means explaining how all aspects of the cell (inside and outside) may be impacted by these problems. Please describe in detail how it acts under normal activity, vs the result of increased activity, and WHY it might increase in activity

Increased activity of mitogen-activated protein kinase(s)

Answer 1

Mitogen Activated Protein Kinases (MAPK) are a family of protein kinases that can phosphorylate downstream effector proteins in a signaling pathway, specifically at serine/threonine amino acid residues, thereby regulating a number of cellular events. The general stimuli for the activation of MAPK are mitogens (which can induce mitotic cell division), heat and osmotic stress or proinflammatory cytokines. MAPK are involved in the control and regulation of many important cellular events including mitosis, cell proliferation, cell differentiation, and apoptosis.

The following are the events inside a cell, under the normal and increased activity of MAPK

• In response to the binding of growth factors to the membrane-bound receptors on the cell, MAPK gets activated and the downstream signalling leads to mitotic cell division. Under increased activity of MAPK, MAPK constantly remains activated and the downstream signaling cascade is always active. This leads to uncontrolled cell divisions and ultimately the cell becomes cancerous.
• When the cell is under stress, that is under oxidative stress or when proinflammatory cytokines are present, MAPK gets activated and initiates a stress response. When MAPK shows normal activity, under stress it signals the cell to apoptosis, migration or proliferation depending on the cell type. Under increased activity of MAPK, it can either lead to the continuous proliferation of the cell which is again cancerous in nature or lead to apoptosis.