Final Answer:
Fas, a death receptor in the tumor necrosis factor family, triggers apoptosis by binding to Fas ligand. Thus, the correct option is a) Fas.
Step-by-step explanation:
The death receptor of the tumor necrosis factor family is Fas. Fas, also known as CD95 or APO-1, plays a crucial role in apoptosis (programmed cell death). When Fas ligand (FasL) binds to Fas, it triggers a signaling cascade that ultimately leads to cell death. This process is essential for the regulation of cell populations and the elimination of damaged or potentially harmful cells.
In the context of apoptosis, Fas serves as a cell surface receptor that activates the caspase cascade, leading to the controlled dismantling of the cell. Upon FasL binding, Fas undergoes a conformational change that allows it to recruit and activate initiator caspases, particularly caspase-8. Activated caspase-8 then activates downstream effector caspases, such as caspase-3, which execute the final steps of apoptosis by cleaving various cellular substrates.
Understanding the role of Fas in apoptosis is crucial for biomedical research, as dysregulation of apoptosis can contribute to various diseases, including cancer and autoimmune disorders. Targeting the Fas-FasL pathway has therapeutic implications, and research in this area continues to explore ways to modulate apoptosis for medical interventions. In summary, the identification of Fas as the death receptor underscores its significance in orchestrating programmed cell death, a fundamental process in maintaining tissue homeostasis and preventing the proliferation of abnormal cells.
Thus, the correct option is a) Fas.