Do humans have caspase 11?
Caspase-11 has been cloned and identified in mice [60] and caspase-4/-5 has been identified in humans, both of which have showed up to 60% homology in amino acid sequence [61, 62] (Fig. 3).
What are the roles of the 2 main caspases?
The caspases can be divided into two groups: initiator caspases, including caspase-1, -8, -9 and -10, and executioner caspases, such as caspase-3 and -7 [4]. Executioner caspases are responsible for the cleavage of numerous structural and regulatory proteins, required to dismantle the cell [1].
What Bond does Caspase 2 modify?
(A) Caspase-2 is linked via its CARD to receptor-interacting protein-associated Ich-1/Ced-3-homologue proteins with a death domain (RAIDD) which in turn associates with p53-induced proteins with a death domain (PIDD) via its death domain (DD).
Which caspases are executioner?
Caspases 2, 8, 9, 10, 11 and 12 are known to be initiators, and caspases 3, 6 and 7 are known to be executioners [17, 18]. Usually, caspases are present in cells as zymogens and require proteolytic cleavage to be converted into active enzymes [18, 19].
What does the inflammasome do?
The inflammasomes are innate immune system receptors/sensors that regulate the activation of caspase-1 and induce inflammation in response to infectious microbes and molecules derived from host proteins. It has been implicated in a host of inflammatory disorders.
What are caspase-3 and 9?
After activation by caspase-9, caspase-3 inhibits ROS production and is required for efficient execution of apoptosis, while effector caspase-7 is required for apoptotic cell detachment.
Why is caspase-3 the executioner?
Caspase-3 is known as an executioner caspase in apoptosis because of its role in coordinating the destruction of cellular structures such as DNA fragmentation or degradation of cytoskeletal proteins (1).
What class of enzymes does caspase-2 belong to?
Caspase-2 is classified as an initiator caspase, which respond to apoptotic stimuli by initiating the apoptotic cascade. Like other caspases, caspase-2 is comprised of an N-terminal prodomain and a large and small catalytic subunit.
What type of enzyme is caspase?
protease enzymes
Caspases, also as cysteine-aspartic proteases, cysteine aspartases or cysteine-dependent aspartate-directed proteases, are a family of protease enzymes that provide critical links in cell regulatory networks controlling inflammation and cell death.
Is caspase-9 an initiator?
Caspase-9, the essential initiator caspase required for apoptosis signalling through the mitochondrial pathway, is activated on the apoptosome complex, and failure to activate caspase-9 has profound pathophysiological consequences.
What is the role of caspase-7?
Main function of caspase-7 involves ROS production and aids in cell detachment during apoptosis (Brentnall et al., 2013). The activation of procaspase-7 is initiated by spontaneous anti-parallel dimerization of two precursor forms.
Why is caspase so named?
They are named caspases due to their specific cysteine protease activity – a cysteine in its active site nucleophilically attacks and cleaves a target protein only after an aspartic acid residue.
What is the function of caspase 11?
Caspase-11, also termed the non-canonical inflammasome, is activated by TLR3 / TLR4 – TRIF signaling and directly binds cytosolic lipopolysaccharide (LPS), a major structural element of Gram-negative bacterial cell walls.
What is the pathophysiology of LPs activation of caspase 11?
Activation of caspase-11 by LPS is known to cause the activation of other caspase proteins, leading to septic shock, pyroptosis, and often organismal death.
What cytokines are produced when caspase 11 is activated?
Caspase-11 activation results in pyroptosis, a form of lytic cell death that releases inflammatory molecules such as ATP, HMGB1 and IL-1α from the cytosol. Inflammatory cytokines such as IL-1β and IL-18 are also often produced.