Regulation of the catalytic domain of protein phosphatase 1 by the terminal region of protein phosphatase 2B

2012 ◽  
Vol 151 (3) ◽  
pp. 283-290 ◽  
Author(s):  
B. J. Wang ◽  
W. Tang ◽  
P. Zhang ◽  
Q. Wei
Keyword(s):  
Protein Phosphatase ◽  
Catalytic Domain ◽  
Terminal Region ◽  
Protein Phosphatase 1 ◽  
Protein Phosphatase 2B

scholarly journals Protein phosphatase 2A is a specific protamine-kinase-inactivating phosphatase

1992 ◽  
Vol 287 (3) ◽  
pp. 1019-1022 ◽  
Author(s):  
G D Amick ◽  
S A G Reddy ◽  
Z Damuni
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Protein Phosphatase ◽  
Kinase Activity ◽  
Protein Phosphatase 2A ◽  
Tyrosine Phosphatase ◽  
Protein Phosphatase 1 ◽  
Protein Phosphatase 2B ◽  
2B Protein ◽  
Phosphatase 2A ◽  
Protamine Kinase

Purified preparations of a protamine protein kinase from bovine kidney cytosol [Damuni, Amick & Sneed (1989) J. Biol. Chem. 264, 6412-6416] were inactivated after incubation with near-homogeneous preparations of protein phosphatase 2A1 and protein phosphatase 2A2. These protein phosphatase 2A-mediated inactivations of the protamine kinase were unaffected by highly purified preparations of inhibitor 2, but were prevented when the incubations were performed in the presence of 100 nM microcystin-LR, 100 nM okadaic acid or 0.2 mM-ATP. By contrast, highly purified preparations of protein phosphatase 2B, protein phosphatase 2C, the catalytic subunit of protein phosphatase 1, and two forms of a protein tyrosine phosphatase, designated PTPase 1B and T-cell PTPase, had little effect, if any, on protamine kinase activity. Purified preparations of the protamine kinase did not react with anti-phosphotyrosine antibodies, as determined by Western blotting and immunoprecipitation analysis. The results indicate that protein phosphatase 2A is a specific protamine-kinase-inactivating phosphatase.

scholarly journals Protein Phosphatase 1 Regulates Human Cytomegalovirus Protein Translation by Restraining AMPK Signaling

2021 ◽  
Vol 12 ◽  
Author(s):  
Carmen Stecher ◽  
Sanja Marinkov ◽  
Lucia Mayr-Harting ◽  
Ana Katic ◽  
Marie-Theres Kastner ◽  
...  
Keyword(s):  
Human Cytomegalovirus ◽  
Protein Phosphatase ◽  
Catalytic Domain ◽  
Human Fibroblasts ◽  
Elongation Factor ◽  
Early Time ◽  
Protein Translation ◽  
Protein Phosphatase 1 ◽  
Ampk Signaling ◽  
Protein Protein Interaction

Human cytomegalovirus (HCMV) carries the human protein phosphatase 1 (PP1) and other human proteins important for protein translation in its tegument layer for a rapid supply upon infection. However, the biological relevance behind PP1 incorporation and its role during infection is unclear. Additionally, PP1 is a difficult molecular target due to its promiscuity and similarities between the catalytic domain of multiple phosphatases. In this study, we circumvented these shortcomings by using 1E7-03, a small molecule protein–protein interaction inhibitor, as a molecular tool of noncatalytic PP1 inhibition. 1E7-03 treatment of human fibroblasts severely impaired HCMV replication and viral protein translation. More specifically, PP1 inhibition led to the deregulation of metabolic signaling pathways starting at very early time points post-infection. This effect was at least partly mediated by the prevention of AMP-activated protein kinase dephosphorylation, leading to elongation factor 2 hyperphosphorylation and reduced translation rates. These findings reveal an important mechanism of PP1 for lytic HCMV infection.

Cloning and identification of MYPT3: a prenylatable myosin targetting subunit of protein phosphatase 1

2001 ◽  
Vol 356 (1) ◽  
pp. 257-267 ◽  
Author(s):  
Jeffrey A. SKINNER ◽  
Alan R. SALTIEL
Keyword(s):  
Molecular Mass ◽  
Protein Phosphatase ◽  
Biochemical Characterization ◽  
Terminal Region ◽  
Protein Phosphatase 1 ◽  
Chromosome 15 ◽  
Glutathione S Transferase ◽  
Interacting Protein

To identify novel protein phosphatase 1 (PP1)-interacting proteins, a yeast two-hybrid 3T3-L1 adipocyte cDNA library was screened with the catalytic subunit of PP1 as bait. In the present work, the isolation, identification and initial biochemical characterization of a novel PP1-interacting protein, MYPT3, which is homologous with the myosin phosphatase targetting subunit (MYPT) family, is described. MYPT3 aligns > 99% with a region of mouse genomic DNA clone RP23-156P23 and localizes to chromosome 15, between markers at 44.1–46.5cM, as demonstrated by radiation hybrid mapping. The gene consists of ten exons that encode for a 524-amino acid sequence with a predicted molecular mass of 57529Da. The N-terminal region of MYPT3 consists of a consensus PP1-binding site and multiple ankyrin repeats. MYPT3 is distinguished from related ∼ 110–130kDa MYPT subunits by its molecular mass of 58kDa, and a unique C-terminal region that contains several potential signalling motifs and a CaaX prenylation site. We have shown that affinity-purified glutathione S-transferase (GST)–MYPT3 is prenylated by purified recombinant farnesyltransferase in vitro. Endogenous PP1 from 3T3-L1 lysates specifically interacts with MYPT3. Additionally, purified PP1 activity was inhibited by GST–MYPT3 toward phosphorylase a, myosin light chain and myosin substrate in vitro. Overall, our findings identify a novel prenylatable subunit of PP1 that defines a new subfamily of MYPT.

scholarly journals The nonconserved N-terminus of protein phosphatase 2B confers its properties to protein phosphatase 1

IUBMB Life ◽  
2009 ◽  
Vol 61 (2) ◽  
pp. 178-183 ◽  
Author(s):  
Xiu-Jie Xie ◽  
Wei Huang ◽  
Cheng-Zhe Xue ◽  
Qun Wei
Keyword(s):  
Protein Phosphatase ◽  
Protein Phosphatase 1 ◽  
Protein Phosphatase 2B ◽  
N Terminus

Apoptosis-associated tyrosine kinase scaffolding of protein phosphatase 1 and SPAK reveals a novel pathway for Na-K-2C1 cotransporter regulation

2007 ◽  
Vol 292 (5) ◽  
pp. C1809-C1815 ◽  
Author(s):  
Kenneth B. E. Gagnon ◽  
Roger England ◽  
Lisa Diehl ◽  
Eric Delpire
Keyword(s):  
Xenopus Laevis ◽  
Tyrosine Kinase ◽  
Protein Interaction ◽  
Protein Phosphatase ◽  
Catalytic Domain ◽  
Protein Phosphatase 1 ◽  
Xenopus Laevis Oocytes ◽  
Physical Interaction ◽  
Protein Protein Interaction ◽  
Key Residues

Previous work from our laboratory and others has established that Ste-20-related proline-alanine-rich kinase (SPAK/PASK) is central to the regulation of NKCC1 function. With no lysine (K) kinase (WNK4) has also been implicated in the regulation of NKCC1 activity through upstream activation of SPAK. Because previous studies from our laboratory also demonstrated a protein-protein interaction between SPAK and apoptosis-associated tyrosine kinase (AATYK), we explore here the possibility that AATYK is another component of the regulation of NKCC1. Heterologous expression of AATYK1 in NKCC1-injected Xenopus laevis oocytes markedly inhibited cotransporter activity under isosmotic conditions. Interestingly, mutation of key residues in the catalytic domain of AATYK1 revealed that the kinase activity does not play a role in the suppression of NKCC1 function. However, mutagenesis of the two SPAK-binding motifs in AATYK1 completely abrogated this effect. As protein phosphatase 1 (PP1) also plays a central role in the dephosphorylation and inactivation of NKCC1, we investigated the possibility that AATYK1 interacts with the phosphatase. We identified a PP1 docking motif in AATYK1 and demonstrated interaction using yeast-2-hybrid analysis. Mutation of a key valine residue (V1175) within this motif prevented protein-protein interaction. Furthermore, the physical interaction between PP1 and AATYK was required for inhibition of NKCC1 activity in Xenopus laevis oocytes. Taken together, our data are consistent with AATYK1 indirectly inhibiting the SPAK/WNK4 activation of the cotransporter by scaffolding an inhibitory phosphatase in proximity to a stimulatory kinase.

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