calmodulin-dependent protein phosphatase activity
Definition
Target type: molecularfunction
Catalysis of the reaction: protein serine/threonine phosphate + H2O = protein serine/threonine + phosphate, dependent on the presence of calcium-bound calmodulin. [GOC:mah, PMID:15359118]
Calmodulin-dependent protein phosphatase (CaM-PP) activity is a crucial regulatory mechanism in cellular signaling. These enzymes are members of the protein phosphatase family, which catalyze the removal of phosphate groups from protein substrates. The defining characteristic of CaM-PPs is their dependence on the calcium-binding protein calmodulin (CaM) for their activity.
CaM acts as a molecular switch, binding to CaM-PPs in response to increases in intracellular calcium concentrations. This binding event triggers a conformational change in the phosphatase, activating its catalytic activity. The activated enzyme can then dephosphorylate a wide range of protein substrates, modulating their activity and function.
CaM-PPs play diverse roles in cellular processes, including:
* **Signal transduction:** De-phosphorylation of target proteins involved in signal transduction pathways, such as kinases, phosphatases, and ion channels.
* **Muscle contraction:** Regulation of muscle contraction by de-phosphorylation of myosin light chain, a key component of the contractile apparatus.
* **Cellular growth and differentiation:** Control of cell growth and differentiation by de-phosphorylation of proteins involved in these processes.
* **Synaptic plasticity:** Modulation of synaptic plasticity in the nervous system by de-phosphorylating proteins involved in neuronal communication.
The molecular function of CaM-PPs involves a complex interplay between calcium, calmodulin, and protein substrates. By specifically removing phosphate groups from target proteins, CaM-PPs finely tune cellular responses to various stimuli, playing a critical role in maintaining cellular homeostasis and mediating diverse physiological functions.'
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Proteins (3)
| Protein | Definition | Taxonomy |
|---|---|---|
| Serine/threonine-protein phosphatase 2B catalytic subunit alpha isoform | A protein phosphatase 3 catalytic subunit alpha that is encoded in the genome of human. [PRO:CNA, UniProtKB:Q08209] | Homo sapiens (human) |
| Protein phosphatase 1A | A protein phosphatase 1A that is encoded in the genome of human. [PRO:DNx, UniProtKB:P35813] | Homo sapiens (human) |
| Serine/threonine-protein phosphatase 2B catalytic subunit beta isoform | A serine/threonine-protein phosphatase 2B catalytic subunit beta isoform that is encoded in the genome of human. [PRO:DNx, UniProtKB:P16298] | Homo sapiens (human) |
Compounds (5)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| cyanoginosin lr | cyanoginosin LR: cyclic heptapeptide from cyanobacterium Microcystis aeruginosa microcystin-LR : A microcystin consisting of D-alanyl, L-leucyl, (3S)-3-methyl-D-beta-aspartyl,L-arginyl, 2S,3S,4E,6E,8S,9S)-3-amino-4,5,6,7-tetradehydro-9-methoxy-2,6,8-trimethyl-10-phenyldecanoyl, D-gamma-glutamyl, and 2,3-didehydro-N-methylalanyl residues joined into a 25-membered macrocycle. Produced by the cyanobacterium Microcystis aeruginosa, it is the most studied of the microcystins. | microcystin | bacterial metabolite; EC 3.1.3.16 (phosphoprotein phosphatase) inhibitor; environmental contaminant; xenobiotic |
| tacrolimus | tacrolimus (anhydrous) : A macrolide lactam containing a 23-membered lactone ring, originally isolated from the fermentation broth of a Japanese soil sample that contained the bacteria Streptomyces tsukubaensis. Tacrolimus: A macrolide isolated from the culture broth of a strain of Streptomyces tsukubaensis that has strong immunosuppressive activity in vivo and prevents the activation of T-lymphocytes in response to antigenic or mitogenic stimulation in vitro. | macrolide lactam | bacterial metabolite; immunosuppressive agent |
| tamoxifen | stilbenoid; tertiary amino compound | angiogenesis inhibitor; antineoplastic agent; bone density conservation agent; EC 1.2.3.1 (aldehyde oxidase) inhibitor; EC 2.7.11.13 (protein kinase C) inhibitor; estrogen antagonist; estrogen receptor antagonist; estrogen receptor modulator | |
| cyclosporine | ramihyphin A: one of the metabolites produced by Fusarium sp. S-435; RN given refers to cpd with unknown MF | homodetic cyclic peptide | anti-asthmatic drug; anticoronaviral agent; antifungal agent; antirheumatic drug; carcinogenic agent; dermatologic drug; EC 3.1.3.16 (phosphoprotein phosphatase) inhibitor; geroprotector; immunosuppressive agent; metabolite |
| bi 201335 | faldaprevir: inhibits hepatitis C virus NS3 protease |