myosin II filament disassembly
Definition
Target type: biologicalprocess
The disassembly of a bipolar filament composed of myosin II molecules. [GOC:mah]
Myosin II filament disassembly is a complex process that involves the coordinated action of multiple proteins and regulatory mechanisms. This process is crucial for various cellular functions, including muscle relaxation, cell migration, and cytokinesis. Here's a detailed description:
1. **Phosphorylation of regulatory light chains:** Myosin II filaments are composed of myosin II molecules, each with two heavy chains and two pairs of light chains: essential light chains (ELCs) and regulatory light chains (RLCs). Phosphorylation of RLCs by myosin light chain kinase (MLCK) triggers filament assembly. However, dephosphorylation of RLCs by myosin light chain phosphatase (MLCP) initiates filament disassembly.
2. **Binding of caldesmon and calponin:** These proteins bind to the myosin II filaments and act as inhibitors of actomyosin ATPase activity. When bound to the filaments, they promote disassembly.
3. **Increased intracellular calcium concentration:** This activates calmodulin, which in turn activates MLCP. The increased MLCP activity leads to dephosphorylation of RLCs and filament disassembly.
4. **Actin depolymerization:** The disassembly of actin filaments, which are essential for myosin II filament assembly, also contributes to the disassembly process. This can occur through the action of actin-depolymerizing factors like cofilin.
5. **Changes in pH:** A decrease in intracellular pH can also promote myosin II filament disassembly.
6. **Mechanical stress:** Excessive mechanical stress on the filaments can lead to their disassembly.
7. **Other factors:** Other proteins, such as tropomyosin and troponin, can also influence myosin II filament disassembly in specific cellular contexts.
In summary, myosin II filament disassembly is a tightly regulated process that is influenced by a variety of factors, including phosphorylation state, protein binding, intracellular calcium concentration, actin dynamics, and mechanical forces. The disassembly process ensures proper regulation of cellular functions such as muscle relaxation and cell motility.'
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Proteins (1)
| Protein | Definition | Taxonomy |
|---|---|---|
| Eukaryotic elongation factor 2 kinase | An elongation factor 2 kinase that is encoded in the genome of human. [PRO:DNx, UniProtKB:O00418] | Homo sapiens (human) |
Compounds (7)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| rottlerin | rottlerin : A chromenol that is 2,2-dimethyl-2H-chromene substituted by hydroxy groups at positions 5 and 7, a 3-acetyl-2,4,6-trihydroxy-5-methylbenzyl group at position 6 and a (1E)-3-oxo-1-phenylprop-1-en-3-yl group at position 8. A potassium channel opener, it is isolated from Mallotus philippensis. rottlerin: an angiogenesis inhibitor; an inhibitor of protein kinase Cdelta (PKCdelta) and calmodulin kinase III; RN refers to (E)-isomer; do not confuse this chalcone with an anthraquinone that is also called rottlerin (RN 481-72-1); | aromatic ketone; benzenetriol; chromenol; enone; methyl ketone | anti-allergic agent; antihypertensive agent; antineoplastic agent; apoptosis inducer; K-ATP channel agonist; metabolite |
| nh 125 | NH 125: structure in first source | ||
| a-484954 | A-484954: eEF2K inhibitor; structure in first source | ||
| entrectinib | entrectinib : A member of the class of indazoles that is 1H-indazole substituted by [4-(4-methylpiperazin-1-yl)-2-(tetrahydro-2H-pyran-4-ylamino)benzoyl]amino and 3,5-difluorobenzyl groups at positions 3 and 5, respectively. It is a potent inhibitor of TRKA, TRKB, TRKC, ROS1, and ALK (IC50 values of 0.1 to 1.7 nM), and used for the treatment of NTRK, ROS1 and ALK gene fusion-positive solid tumours. entrectinib: inhibits TRK, ROS1, and ALK receptor tyrosine kinases; structure in first source | benzamides; difluorobenzene; indazoles; N-methylpiperazine; oxanes; secondary amino compound; secondary carboxamide | antibacterial agent; antineoplastic agent; apoptosis inducer; EC 2.7.10.1 (receptor protein-tyrosine kinase) inhibitor |
| nms p937 | NMS P937: a polo-like kinase 1 inhibitor; structure in first source | ||
| nms-p118 | NMS-P118: a PARP-1 inhibitor; structure in first source | ||
| nms-e973 | NMS-E973: structure in first source |