Regulation cascade

The different pro- and anticoagulatory systems are complex regulated cascades involving blood cells (platelets, monocytes, endothelial cells), enzymes, cofactors, phospholipids, and calcium, which interact with each other... 

It is clear that, as understanding of the underlying principles of both iminium ion and enamine catalysis improves, the trae power of these cascade sequences will be fully exploited. It can be expected that introduction of subsequent independent catalytic cycles will add to the complexity and applicabihty of these processes and provide highly regulated cascades that mimic the power of enzymatic pathways. 

Complement acts to kill bacterial cells that are missed by the neutrophils and the macrophages. There arc actually two separate complement pathways. One. the classical pathway, operates in the adaptive or acquired immune response. The elas.sieal pathway has an absolute requirement fur an Ab-an-tigen complex as a trigger. The other, the alieriimive pathway. requires no Ah or antigen to initiate and is operative in innate immunity. Both pathways operate in a tightly regulated cascade fashion. The proteins normally circulate as inactive proenzymes. When the pathways are activated, the product of each step activates the subsequent step. 

S ATP + dephospho-[[hydroxymethylglutaryl-CoA reductase (NADPH)] kinase] <1, 2> (<1,2> phosphorylation activates EC 2.7.1.109 [1-8] <1> involved in regulation cascade of hydroxymethylglutaryl-CoA reductase, EC 1.1.1.34 [2] <1> important for the responses of cells to metabolic stresses such as lack of ceU nutrients, hypoxia, ischemia and muscular exercise [9] <1> bicyclic phosporylation system, enzyme is believed to be involved in protecting cells against ATP depletion due to environmental stress by inactivating several key biosynthetic enzymes [7]) [1-9]... 

Davie E W, Fu]lkawa K and KIslel W 1991 The coagulation cascade Initiation, maintenance and regulation 1991 Bioohemistry 30 10 363-10 370... 

Mitogen activated protein kinase (MARK) cascades are three kinase modules activated by phosphorylation. The three kinase modules are composed of a MAPK, a MAPKK, and a MAPKKK. There are multiple members of each component of the MAPK cascade that are conserved from yeast to human. Activation of selective MAPK modules by specific stimuli regulates cell functions such as gene expression, adhesion, migration, differ entiation, and apoptosis. 

MAPK cascades are composed of three cytoplasmic kinases, the MAPKKK, MAPKK, and MAPK, that are regulated by phosphorylation (Fig. 1) [1, 2]. The MAPKKK, also called MEKK for MEK kinase, is a serine/threonine kinase. Selective activation of MAPKKKs by upstream cellular stimuli results in the phosphorylation of MAPKK, also called MEK for MAP/ERK kinase by the MAPKKK. MAPKKK members are structurally diverse and are differentially regulated by specific upstream stimuli. The MAPKK is phosphorylated by the MAPKKK on two specific serine/ threonine residues in its activation loop. The MAPKK family members are dual specificity kinases capable of phosphorylating critical threonine and tyrosine residues in the activation loop of the MAPKs. MAPKKs have the fewest members in the MAPK signaling module. MAPKs are a family of serine/threonine kinases that upon activation by their respective MAPKKs, are capable of phosphorylating cytoplasmic substrates as well as... 

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