scholarly journals Identification of the Major Phosphorylation Site in Bcl-xL Induced by Microtubule Inhibitors and Analysis of Its Functional Significance

2008 ◽  
Vol 283 (51) ◽  
pp. 35517-35525 ◽  
Author(s):  
Meenakshi Upreti ◽  
Elena N. Galitovskaya ◽  
Rong Chu ◽  
Alan J. Tackett ◽  
David T. Terrano ◽  
...  
Keyword(s):  
Functional Significance ◽  
Phosphorylation Site ◽  
Microtubule Inhibitors ◽  
Major Phosphorylation Site

scholarly journals Phosphorylation at Serine 10, a Major Phosphorylation Site of p27Kip1, Increases Its Protein Stability

2000 ◽  
Vol 275 (33) ◽  
pp. 25146-25154 ◽  
Author(s):  
Noriko Ishida ◽  
Masatoshi Kitagawa ◽  
Shigetsugu Hatakeyama ◽  
Kei-ichi Nakayama
Keyword(s):  
Protein Stability ◽  
Phosphorylation Site ◽  
Major Phosphorylation Site

scholarly journals New insights into the phosphorylation of the threonine motif of the β1 integrin cytoplasmic domain

2022 ◽  
Vol 5 (4) ◽  
pp. e202101301
Author(s):  
Ralph T Böttcher ◽  
Nico Strohmeyer ◽  
Jonas Aretz ◽  
Reinhard Fässler
Keyword(s):  
Mass Spectrometry ◽  
Ligand Binding ◽  
Phosphorylation Site ◽  
Cell Spreading ◽  
Mouse Cell ◽  
Β1 Integrin ◽  
Β1 Integrins ◽  
Integrin Ligand ◽  
Human And Mouse ◽  
Major Phosphorylation Site

Integrins require an activation step before ligand binding and signaling that is mediated by talin and kindlin binding to the β integrin cytosolic domain (β-tail). Conflicting reports exist about the contribution of phosphorylation of a conserved threonine motif in the β1-tail (β1-pT788/pT789) to integrin activation. We show that widely used and commercially available antibodies against β1-pT788/pT789 integrin do not detect specific β1-pT788/pT789 integrin signals in immunoblots of several human and mouse cell lysates but bind bi-phosphorylated threonine residues in numerous proteins, which were identified by mass spectrometry experiments. Furthermore, we found that fibroblasts and epithelial cells expressing the phospho-mimicking β1-TT788/789DD integrin failed to activate β1 integrins and displayed reduced integrin ligand binding, adhesion initiation and cell spreading. These cellular defects are specifically caused by the inability of kindlin to bind β1-tail polypeptides carrying a phosphorylated threonine motif or phospho-mimicking TT788/789DD substitutions. Our findings indicate that the double-threonine motif in β1-class integrins is not a major phosphorylation site but if phosphorylated would curb integrin function.

scholarly journals Roles of Phosphorylation of the Nucleocapsid Protein of Mumps Virus in Regulating Viral RNA Transcription and Replication

2015 ◽  
Vol 89 (14) ◽  
pp. 7338-7347 ◽  
Author(s):  
James Zengel ◽  
Adrian Pickar ◽  
Pei Xu ◽  
Alita Lin ◽  
Biao He
Keyword(s):  
Nucleocapsid Protein ◽  
Rna Synthesis ◽  
Critical Role ◽  
Phosphorylation Site ◽  
Mumps Virus ◽  
Viral Rna ◽  
Human Populations ◽  
Rna Genome ◽  
Major Phosphorylation Site ◽  
Transcription And Replication

ABSTRACTMumps virus (MuV) is a paramyxovirus with a negative-sense nonsegmented RNA genome. The viral RNA genome is encapsidated by the nucleocapsid protein (NP) to form the ribonucleoprotein (RNP), which serves as a template for transcription and replication. In this study, we investigated the roles of phosphorylation sites of NP in MuV RNA synthesis. Using radioactive labeling, we first demonstrated that NP was phosphorylated in MuV-infected cells. Using both liquid chromatography-mass spectrometry (LC-MS) andin silicomodeling, we identified nine putative phosphorylated residues within NP. We mutated these nine residues to alanine. Mutation of the serine residue at position 439 to alanine (S439A) was found to reduce the phosphorylation of NP in transfected cells by over 90%. The effects of these mutations on the MuV minigenome system were examined. The S439A mutant was found to have higher activity, four mutants had lower activity, and four mutants had similar activity compared to wild-type NP. MuV containing the S439A mutation had 90% reduced phosphorylation of NP and enhanced viral RNA synthesis and viral protein expression at early time points after infection, indicating that S439 is the major phosphorylation site of NP and its phosphorylation plays an important role in downregulating viral RNA synthesis.IMPORTANCEMumps virus (MuV), a paramyxovirus, is an important human pathogen that is reemerging in human populations. Nucleocapsid protein (NP) of MuV is essential for viral RNA synthesis. We have identified the major phosphorylation site of NP. We have found that phosphorylation of NP plays a critical role in regulating viral RNA synthesis. The work will lead to a better understanding of viral RNA synthesis and possible novel targets for antiviral drug development.

scholarly journals The major phosphorylation site of the NADPH oxidase component p67phox is Thr233

1999 ◽  
Vol 338 (1) ◽  
pp. 99-105 ◽  
Author(s):  
Louisa V. FORBES ◽  
Oanh TRUONG ◽  
Frans B. WIENTJES ◽  
Stephen J. MOSS ◽  
Anthony W. SEGAL
Keyword(s):  
Protein Kinase ◽  
Cyanogen Bromide ◽  
Tryptic Peptide ◽  
Phosphorylation Site ◽  
Mitogen Activated Protein Kinase ◽  
Rich Domain ◽  
Mitogen Activated Protein ◽  
Phosphopeptide Mapping ◽  
Major Phosphorylation Site

Phosphorylation of p67phox was shown to increase two- to three-fold upon stimulation by PMA, N-formylmethionyl-leucylphenylalanine or serum-opsonized zymosan. Phosphopeptide mapping showed one major tryptic peptide for p67phox immunoprecipitated from resting or stimulated cells. In vitro phosphorylation of p67phox by isolated cytosol or mitogen-activated protein kinase also generated the same phosphopeptide. Results of cyanogen bromide digestion and HPLC–MS suggested that Thr233 was the phosphorylated residue. Mutagenesis of Thr233 to alanine resulted in loss of phosphorylation in vitro. In the present work, Thr233 has been identified as the major phosphorylation site of p67phox, which is situated in a proline-rich domain.

scholarly journals Activation of Pre-mRNA Splicing by Human RNPS1 Is Regulated by CK2 Phosphorylation

2005 ◽  
Vol 25 (4) ◽  
pp. 1446-1457 ◽  
Author(s):  
Janeen H. Trembley ◽  
Sawako Tatsumi ◽  
Eiji Sakashita ◽  
Pascal Loyer ◽  
Clive A. Slaughter ◽  
...  
Keyword(s):  
Nuclear Localization ◽  
Phosphorylation Site ◽  
Mrna Splicing ◽  
Exon Junction Complex ◽  
Exon Junction ◽  
In Vivo Experiments ◽  
Splicing Regulator ◽  
Major Phosphorylation Site

ABSTRACT Human RNPS1 was originally characterized as a pre-mRNA splicing activator in vitro and was shown to regulate alternative splicing in vivo. RNPS1 was also identified as a protein component of the splicing-dependent mRNP complex, or exon-exon junction complex (EJC), and a role for RNPS1 in postsplicing processes has been proposed. Here we demonstrate that RNPS1 incorporates into active spliceosomes, enhances the formation of the ATP-dependent A complex, and promotes the generation of both intermediate and final spliced products. RNPS1 is phosphorylated in vivo and interacts with the CK2 (casein kinase II) protein kinase. Serine 53 (Ser-53) of RNPS1 was identified as the major phosphorylation site for CK2 in vitro, and the same site is also phosphorylated in vivo. The phosphorylation status of Ser-53 significantly affects splicing activation in vitro, but it does not perturb the nuclear localization of RNPS1. In vivo experiments indicated that the phosphorylation of RNPS1 at Ser-53 influences the efficiencies of both splicing and translation. We propose that RNPS1 is a splicing regulator whose activator function is controlled in part by CK2 phosphorylation.

scholarly journals Phosphorylation of serine-167 on the human oestrogen receptor is important for oestrogen response element binding and transcriptional activation

1997 ◽  
Vol 326 (1) ◽  
pp. 149-157 ◽  
Author(s):  
Enrique CASTAÑO ◽  
Daria P. VOROJEIKINA ◽  
Angelo C. NOTIDES
Keyword(s):  
Dna Binding ◽  
Transcriptional Activation ◽  
Functional Significance ◽  
Oestrogen Receptor ◽  
Phosphorylation Site ◽  
Casein Kinase Ii ◽  
Casein Kinase ◽  
Hormone Binding ◽  
Dna Binding Affinity

We have studied the role of phosphorylation of the human oestrogen receptor (hOR; otherwise known as hER) at serine-167, which has been identified previously as the major oestrogen-induced phosphorylation site. We have tested transactivation by the hOR in yeast and cell-free transcription assays, and shown that mutation of serine-167 results in a 70% decrease in hOR-dependent transcription. Furthermore we explored the functional significance of phosphorylation at this site by hormone binding and DNA binding. DNA binding affinity was 10-fold lower when serine-167 was changed to alanine in the hOR. Cell-free transcription experiments showed that casein kinase II is the enzyme responsible for oestradiol-dependent phosphorylation of the hOR at serine-167. This suggests that a conformational change of the hOR must occur upon hormone binding that exposes serine-167 to casein kinase II, resulting in transactivation of oestrogen-responsive genes.

scholarly journals Ser-59 is the major phosphorylation site in αB-crystallin accumulated in the brains of patients with Alexander's disease

2008 ◽  
Vol 76 (3) ◽  
pp. 730-736 ◽  
Author(s):  
Kanefusa Kato ◽  
Yutaka Inaguma ◽  
Hidenori Ito ◽  
Kayo Iida ◽  
Ikuko Iwamoto ◽  
...  
Keyword(s):  
Phosphorylation Site ◽  
Alexander's Disease ◽  
Αb Crystallin ◽  
Major Phosphorylation Site
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