What initiates extrinsic pathway of apoptosis?
The extrinsic pathway that initiates apoptosis is triggered by a death ligand binding to a death receptor, such as TNF-α to TNFR1. The TNFR family is a large family consisting of 29 transmembrane receptor proteins, organized in homotrimers and activated by binding of the respective ligand(s).
How can apoptosis be initiated?
Apoptosis can be initiated through one of two pathways. In the intrinsic pathway the cell kills itself because it senses cell stress, while in the extrinsic pathway the cell kills itself because of signals from other cells. Weak external signals may also activate the intrinsic pathway of apoptosis.
Can apoptosis be initiated by stress?
Various types of cellular stress stimuli have been shown to trigger apoptosis, including chemotherapeutic agents, irradiation, oxidative stress, and ER stress.
What triggers the intrinsic pathway of apoptosis?
Intrinsic pathway of apoptosis The intrinsic apoptosis pathway begins when an injury occurs within the cell. Intrinsic stresses such as oncogenes, direct DNA damage, hypoxia, and survival factor deprivation, can activate the intrinsic apoptotic pathway.
What activates the intrinsic pathway?
The intrinsic pathway is activated through exposed endothelial collagen, and the extrinsic pathway is activated through tissue factor released by endothelial cells after external damage. This pathway is the longer pathway of secondary hemostasis.
What is extrinsic pathway?
The extrinsic pathway consists of the transmembrane receptor tissue factor (TF) and plasma factor VII/VIIa (FVII/FVIIa), and the intrinsic pathway consists of plasma FXI, FIX, and FVIII. Under physiological conditions, TF is constitutively expressed by adventitial cells surrounding blood vessels and initiates clotting.
Can you induce apoptosis?
Induction Overview In cell lines intrinsic apoptosis can be induced by stimuli including removing growth factor supplements from cell media, exposure to UV light or by exerting other stressful conditions on the cell as shown on the left of Figure 1.
Which of the following cellular organelles are involved in the initiation of the extrinsic pathway of apoptosis?
Mitochondria. All of the above. Hint:-Apoptosis, which happens in multicellular animals, is a type of programmed cell death.
Does oxidative stress cause apoptosis?
Apoptosis can be triggered by oxidative stress [12] which is caused by excessive production of reactive oxygen species (ROS) such as hydrogen peroxide H2O2, hydroxyl radical OH·, superoxide O2− · and peroxyl RO·. ROS are constantly generated as a consequence of aerobic respiration [13].
What causes extrinsic apoptosis?
The extrinsic pathway of apoptosis begins outside a cell, when conditions in the extracellular environment determine that a cell must die. The intrinsic pathway of apoptosis pathway begins when an injury occurs within the cell and the resulting stress activates the apoptotic pathway.
What activates extrinsic pathway?
The extrinsic pathway is activated by external trauma that causes blood to escape from the vascular system. This pathway is quicker than the intrinsic pathway. It involves factor VII.
How are extrinsic and intrinsic pathways activated?
What initiates extrinsic pathway?
The extrinsic pathway is activated by external trauma that causes blood to escape from the vascular system. This pathway is quicker than the intrinsic pathway.
What factor initiates the extrinsic pathway?
The extrinsic pathway is clinically measured as the prothrombin time (PT). This pathway begins at factor X which is activated to factor Xa. The process of activating factor Xa is a complicated reaction. Tenase is the complex that cleaves factor X into factor Xa.
Which cellular organelles are involved in the initiation of the intrinsic apoptosis?
So, the correct option is ‘ER, lysosome, mitochondria’.
Which caspase is activated in the ER pathway of apoptosis?
Another mechanism of ER-mediated apoptosis involves the caspase-12/caspase-4 pathway [15], [18]. Caspase-12/-4 can be activated by several different mechanisms.
What are the two main pathways of apoptosis?
HIV enzymes deactivate anti-apoptotic Bcl-2.
What are intrinsic and extrinsic pathways?
Intrinsic pathway is one type of blood coagulation pathway that is activated when there is a blood trauma. Extrinsic pathway is a type of blood coagulation pathway that is activated when the traumatized vascular wall or the extra-vascular tissues come into contact with the blood. Efficiency. Intrinsic Pathway is slow.
What activates intrinsic pathway?
Homeodomain Proteins
Which molecule triggers apoptosis Quizlet?
Which molecule triggers apoptosis Quizlet? Mitochondria contain several proteins that are capable of inducing apoptosis; these proteins include cytochrome c and other proteins that neutralize endogenous inhibitors of apoptosis. Cytochrome C is sequestered in the intermembrane space of the mitochondria and Blc-2 is the regulatory factor that