Identification of MYPT1 and NIPP1 as subunits of protein phosphatase 1 in rat liver cytosol

Boudrez, An; Evens, Kristien; Beullens, Monique; Waelkens, Etienne; Stalmans, Willy

doi:10.1016/s0014-5793(99)00875-3

Cited by 18 publications

(9 citation statements)

References 27 publications

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“…PP1 dephosphorylates Ser/Thr residues on a variety of proteins and the timely regulation of these dephosphorylation events is thought to be controlled by the association of PP1 with small regulatory subunits such as NIPP‐1 [74,75]. The subcellular localization of NIPP‐1 is striking being mainly in nuclear speckles, which are sites of splicing or storage of splicing factors [74,75]. It has therefore been proposed that NIPP‐1 specifically targets PP1 to the splicing apparatus and that PP1 acts as a regulator of pre‐mRNA splicing.…”

Section: Eukaryotic Fha‐containing Proteinsmentioning

confidence: 99%

The FHA domain

Durocher¹,

Jackson²

2001

FEBS Letters

378

206

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The forkhead-associated (FHA) domain is a small protein module recently shown to recognize phosphothreonine epitopes on proteins. It is present in a diverse range of proteins in eukaryotic cells, such as kinases, phosphatases, kinesins, transcription factors, RNA-binding proteins, and metabolic enzymes. It is also found in a number of bacterial proteins. This suggests that FHA domain-mediated phospho-dependent assembly of protein complexes is an ancient and widespread regulatory mechanism. ß 2002 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.

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Section: Eukaryotic Fha‐containing Proteinsmentioning

confidence: 99%

The FHA domain

Durocher¹,

Jackson²

2001

FEBS Letters

378

206

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“…For example, PP1c complexed with a large subunit similar to MYPT that localized to the cytoskeletal and membrane fractions was identified in human platelets [13]. Recently, the presence of MYPT was also shown in the cytosolic fraction of rat liver [14]. There are two genes for MYPT [11] and these are located on human chromosome 12 (MYPT1) and chromosome 1 (MYPT2).…”

mentioning

confidence: 99%

Study of the subunit interactions in myosin phosphatase by surface plasmon resonance

Tóth¹,

Kiss²,

Herberg³

et al. 2000

European Journal of Biochemistry

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The interactions of the catalytic subunit of type 1 protein phosphatase (PP1c) and the N-terminal half (residues 1±511) of myosin phosphatase target subunit 1 (MYPT1) were studied. Biotinylated MYPT1 derivatives were immobilized on streptavidin-biosensor chips, and binding parameters with PP1c were determined by surface plasmon resonance (SPR). The affinity of binding of PP1c was: MYPT1 1±296 . MYPT1 1±38 . MYPT1 23±38 . No binding was detected with MYPT1 1±34 , suggesting a critical role for residues 35±38, i.e. the PP1c binding motif. Binding of residues 1±22 was inferred from: a higher affinity binding to PP1c for MYPT1 1±38 compared to MYPT1 23±38 , as deduced from SPR kinetic data and ligand competition assays; and an activation of the myosin light chain phosphatase activity of PP1c by MYPT1 1±38 , but not by MYPT1 23±38 . Residues 40±296 (ankyrin repeats) in MYPT1 1±296 inhibited the phosphorylase phosphatase activity of PP1c (IC 50 = 0.2 nm), whereas MYPT1 1±38 , MYPT1 23±38 or MYPT1 1±34 were without effect. MYPT1 40±511 , which alone did not bind to PP1c, showed facilitated binding to the complexes of PP1c±MYPT1 1±38 and PP1c±MYPT1 23±38 . The inhibitory effect of MYPT1 40±511 on the phosphorylase phosphatase activity of PP1c also was increased in the presence of MYPT1 1±38 . The binding of MYPT1 304±511 to complexes of PP1c and MYPT1 1±38 , or MYPT1 1±296 , was detected by SPR. These results suggest that within the N-terminal half of MYPT1 there are at least four binding sites for PP1c. The essential interaction is with the PP1c-binding motif and the other interactions are facilitated in an ordered and cooperative manner.Keywords: myosin phosphatase; protein phosphatase-1; myosin phosphatase target subunit-1; surface plasmon resonance.Phosphorylation of the 20-kDa light chains of smooth muscle myosin (MLC20) on Ser19 plays a pivotal role in the regulation of contractile activity of smooth muscle and is also implicated in several functions of nonmuscle cells [1]. The phosphorylation level of myosin reflects the balance of activities of myosin light chain kinase and the myosin phosphatase (MP). Several different preparations of MP that are active with phosphorylated myosin and/or the phosphorylated form of MLC20 (P-MLC20) have been isolated from smooth muscle [2]. Recently several groups have suggested that the major form of MP in smooth muscle is a trimeric holoenzyme composed of the 38-kDa d isoform of type 1 protein phosphatase catalytic subunit (PP1cd), a large subunit of 110/133 kDa, and a small subunit of 20/21 kDa [3±6]. The 20/21 kDa subunit interacts with the large subunit and its function is not known [7,8]. The 110/133 kDa subunit binds to both the catalytic subunit of type 1 protein phosphatase (PP1c) and myosin [7±10] and thus is termed myosin phosphatase target subunit (MYPT) [11,12]. MP is not confined to smooth muscle. For example, PP1c complexed with a large subunit similar to MYPT that localized to the cytoskeletal and membrane fractions was identified in human platelets [13]. Recently,...

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“…The TN concentration was up to 2.84 mg/L and the TP concentration reached 0.04 mg/L because the light intensity and water temperature gradually increased, The algal density was influenced by light intensity and temperature [45][46][47][48]. However, greater light intensity does not mean more vigorous growth of algae.…”

Section: The Annual Variation Of Algal Cells Number In Shibianyu Resementioning

confidence: 99%

Impact of Contaminated Sediment on the Water Quality of Typical Reservoirs

Xia

Zhou

2016

The Handbook of Environmental Chemistry

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The sediment in reservoirs is mainly derived from the sedimentation of suspended grains, such as organic particles and inorganic minerals, carried by runoff scouring from vegetation. There are three parts in this chapter: (1) Effects of pollutants released from sediment on water quality; (2) Effects of metals released from sediment on water quality; (3) Algal blooms and their impact on water quality. The decrease of the oxidation-reduction potential (ORP) in a multiphase interface under anaerobic conditions resulted in the increase of soluble ferrous hydroxide. Phosphate combining with iron hydroxide in sediment is released to interstitial water and then diffused into the overlying water. In addition, the metabolism of microbes resulted in the decrease of the ORP in anaerobic conditions, promoting the release of soluble iron in sediment and then causing the huge release of phosphorus. The release of endogenous phosphorus from sediment under anaerobic conditions resulted in the significant increase of PO 4 3À in the overlying water. The release of phosphorus from sediment depends on the conditions of the ORP. total area of 3.7 km 2 . The maximum design water depth is 32.58 m, and it has a total storage capacity of 4,480,000 m 3 . It was mainly used for irrigation at the beginning of its user, but in recent years, the reservoir has served as a drinking water source due to water shortage.A total of ten representative sampling points at the upstream, midstream, and downstream sections were selected in this study (Table 1). The surface sediment samples were collected by a Pedersen grab type sampler, sealed in the bags, and cryopreserved. The distribution of the sampling points is shown in Fig. 1.The moisture content, ignition loss, and organic content of sediment were determined in the ten sampling points (Fig. 2). The water quality of the interstitial water in sediment was further analyzed (Fig. 3).It can be seen from Figs. 2 and 3 that the differences in the moisture content in sediment are small (with an average of 43 %) due to the different geographic positions and environment conditions. The maximum sediment total nitrogen (STN) is 2.6 mg/g at sampling point S 10 , while the minimum STN is 1.4 mg/g at sampling point S 6 . The average STN is 2.1 mg/g. The maximum SOC is 5.3 % and the minimum SOC is 2.8 %, with an average of 3.8 %. The TN concentration of interstitial water at S 3 , S 6 , S 7 , and S 8 are 18.5 mg/L, 8 mg/L, 7

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Identification of MYPT1 and NIPP1 as subunits of protein phosphatase 1 in rat liver cytosol

Cited by 18 publications

References 27 publications

The FHA domain

The FHA domain

Study of the subunit interactions in myosin phosphatase by surface plasmon resonance

Impact of Contaminated Sediment on the Water Quality of Typical Reservoirs

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