Protein phosphatases types

EGFR Epidermal growth factor receptor PP2A Protein phosphatase, type 2A... 

X. Ai, S.M. Pogwizd, Connexin 43 downregulation and dephosphorylation in nonischemic heart failure is associated with enhanced colocalized protein phosphatase type 2A, Circ Res 96,54-63 (2005). 

Durfee T, Becherer K, Chen PL et al (1993) The retinoblastoma protein associates with the protein phosphatase type 1 catalytic subunit. Genes Dev 7 555-569... 

The myosin phosphatase targeting protein (MYPT) family a regulated mechanism for achieving substrate specificity of the catalytic subunit of protein phosphatase type Idelta. Arch Biochem Biophys 510 147-159... 

Microcystins are also potent tumor promoters that are mediated through the inhibition of the protein phosphatase type 1 and 2A activities. Their mode of action appears to be different from that of other protein phosphatase inhibitors, such as okadaic acid for, example [93], and their effects are organ specific [70,94,95], The incidence of primary liver cancer in China, where people drink pond and ditch water, is about eight times higher than in populations that drink well water [25], and MCs were found in areas were cancer incidence was high [26],... 

Clarke, P. R., Hoffman, I., Draetta, G., and Karsenti, E. (1993). Dephosphorylation of cdc25-C by a type-2A protein phosphatase specific regulation during the cell cycle in Xenopus egg extracts. Mol. Biol. Cell 4 397—411. 

Inhibitor of serine and cysteine proteases plasmin, trypsin, papain and cathepsin B Inhibitor of type 1 and type 2A protein phosphatases... 

Okadaic acid is a powerful tumor promoter of a nonphorbol ester type that inhibits protein phosphatase-1 and -2A in vitro (Haystead et al., 1989). Okadaic acid directly stimulates smooth muscle contraction (Haystead et al., 1989) and probably causes diarrhea, either by stimulating the phosphorylation of proteins controlling sodium secretion by intestinal cells or by increasing phosphorylation of elements that regulate permeability to solutes, resulting in a passive loss of fluids (Aune and Yndestad, 1993). 

In mammalian tissues four different types of protein phosphatases, known as PPl, PP2A, PP2B (or calcineurin), and PP2C, have been identified. Except for PP2C, these enzymes are evolutionary... 

In mammals, at least four groups of Ser/Tlir phosphatases can be differentiated the members of these groups are known as protein phosphatases (PP) 1, 2A, 2B and 2C. PP-1, PP-2A and PP-2B are highly homologous with respect to the sequence of the catalytic domain but they differ in substrate specificity and type of regulation. 

Additionally, a number of marine toxins with medical and toxicological importance have been isolated from marine flora and fauna. Okadaic acid, Fig. (62) is the main toxin produced by dinoflagellates, which can accumulate in the hepatopancreas of mussels and caused diarrhetic shellfish poisoning in consumers [505,506], However, this toxin is also a tumor promoter and a specific potent inhibitor of protein phosphatases which may provokes mitotic arrest and apoptosis of leukemia cells [507-509], These types of compounds have been reported in shellfish and phytoplankton, and more recently, in Spanish mussels [510], Portuguese bivalves [511], and the diatom Thalassiosira weissflogii [512],... 

The assays for the enzyme synthesis of sulfogalactosyl-glycerolipid, sulfatides and galactocerebrosides were carried out as previously described respectively by Subba Rao, et al. (28) Sarlieve, et al. 05, 29), and Neskovic, et al. (30). The assay for 2, 3 cyclic nucleotide phosphohydrolase was performed according to the method of Prohaska, et al. (31). EL coli. alkaline phosphatase type III-S, 2, 3 -cAMP, and sodium deoxycholate were obtained from Sigma (St. Louis, Mo.). Protein was determined by the method of Lowry, et al. (32) with crystalline bovine serum albumin as the standard. 

Christ, T., Boknik, P., Wohrl, S., Wettwer, E., Graf, E. M., Bosch, R. F., Knaut, M., Schmitz, W., Ravens, U., and Dobrev, D. (2004). L-Type Ca2+ Current Downregulation in Chronic Human Atrial Fibrillation is Associated with Increased Activity of Protein Phosphatases. Circulation 110(17) 2651-7. 

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