Growth-factor receptor-bound protein-2 (Grb2) signaling in B cells controls lymphoid follicle organization and germinal center reaction.
AuthorsJang IK, Cronshaw DG, Xie LK, Fang G, Zhang J, Oh H, Fu YX, Gu H, Zou Y
JournalProc Natl Acad Sci U S A
PubMed ID21508326
'Grb2 (growth-factor receptor-bound protein-2) is a signaling adaptor that interacts with numerous receptors and intracellular signaling molecules. However, its role in B-cell development and function remains unknown. Here we show that ablation of Grb2 in B cells results in enhanced B-cell receptor signaling; however, mutant B cells do not form ... More
STN8 protein kinase in Arabidopsis thaliana is specific in phosphorylation of photosystem II core proteins.
AuthorsVainonen JP, Hansson M, Vener AV,
JournalJ Biol Chem
PubMed ID16040609
'Combination of reversed genetics with analyses of in vivo protein phosphorylation in Arabidopsis thaliana revealed that STN8 protein kinase is specific in phosphorylation of N-terminal threonine residues in D1, D2, and CP43 proteins, and Thr-4 in the PsbH protein of photosystem II. Phosphorylation of D1, D2, and CP43 in the ... More
Hyaluronan-mediated CD44 interaction with RhoGEF and Rho kinase promotes Grb2-associated binder-1 phosphorylation and phosphatidylinositol 3-kinase signaling leading to cytokine (macrophage-colony stimulating factor) production and breast tumor progression.
'In this study we have examined CD44 (a hyaluronan (HA) receptor) interaction with a RhoA-specific guanine nucleotide exchange factor (p115RhoGEF) in human metastatic breast tumor cells (MDA-MB-231 cell line). Immunoprecipitation and immunoblot analyses indicate that both CD44 and p115RhoGEF are expressed in MDA-MB-231 cells and that these two proteins are ... More
High-throughput nonradioisotopic detection of picomole levels of phosphothreonine and phosphoserine containing peptides via biotinylation and enzyme-linked immunosorbent assay.
AuthorsMahoney CW, Hosoi T, Ohashi M
JournalAnal Biochem
PubMed ID10075828
'Determination of phosphorylation sites in proteins is usually accomplished using [gamma-32P]ATP. For low-abundance phosphoproteins, in vivo and intact cell studies usually require millicurie levels of 32P for a single experiment, making multiple experiments prohibitive. Here we describe a low picomole sensitivity, nonradioisotopic, high-throughput method for tracing phosphorylation sites in proteins ... More
Aldosterone and tight junctions: modulation of claudin-4 phosphorylation in renal collecting duct cells.
AuthorsLe Moellic C, Boulkroun S, González-Nunez D, Dublineau I, Cluzeaud F, Fay M, Blot-Chabaud M, Farman N,
JournalAm J Physiol Cell Physiol
PubMed ID16107502
'Aldosterone classically modulates Na transport in tight epithelia such as the renal collecting duct (CD) through the transcellular route, but it is not known whether the hormone could also affect paracellular permeability. Such permeability is controlled by tight junctions (TJ) that form a size- and charge-selective barrier. Among TJ proteins, ... More
Characterization and use of monoclonal antibodies for isolation of phosphotyrosyl proteins from retrovirus-transformed cells and growth factor-stimulated cells.
AuthorsFrackelton AR, Ross AH, Eisen HN
JournalMol Cell Biol
PubMed ID6194425
'Protein kinases that phosphorylate the hydroxyl group of tyrosine residues of proteins have been implicated in cell transformation by some retroviruses and in regulation of normal cell growth by some polypeptide growth factors. To facilitate the identification of tyrosine kinase substrates, we developed monoclonal antibodies to the hapten azobenzylphosphonate. One ... More
Signaling cascades activated upon antibody cross-linking of myelin oligodendrocyte glycoprotein: potential implications for multiple sclerosis.
AuthorsMarta CB, Montano MB, Taylor CM, Taylor AL, Bansal R, Pfeiffer SE,
JournalJ Biol Chem
PubMed ID15634682
'Antibody-induced demyelination is an important component of pathology in multiple sclerosis. In particular, antibodies to myelin oligodendrocyte glycoprotein (MOG) are elevated in multiple sclerosis patients, and they have been implicated as mediators of demyelination. We have shown previously that antibody cross-linking of MOG in oligodendrocytes results in the repartitioning of ... More
Protein serine/threonine kinases.
AuthorsEdelman AM, Blumenthal DK, Krebs EG
JournalAnnu Rev Biochem
PubMed ID2956925
Protein kinase classification.
AuthorsHunter T
JournalMethods Enzymol
PubMed ID1835513
Generation and use of antibodies to phosphothreonine.
AuthorsHeffetz D, Fridkin M, Zick Y
JournalMethods Enzymol
PubMed ID1943772
No abstract provided.
Paclitaxel induces inactivation of p70 S6 kinase and phosphorylation of Thr421 and Ser424 via multiple signaling pathways in mitosis.
AuthorsLe XF, Hittelman WN, Liu J, McWatters A, Li C, Mills GB, Bast RC,
JournalOncogene
PubMed ID12555062
The 70 kDa ribosomal S6 kinase (p70S6K) is important for cell growth and survival. Activation of p70S6K requires sequential phosphorylation of multiple serine and threonine sites often triggered by growth factors and hormones. Here, we report that paclitaxel, a microtubule-damaging agent, induces phosphorylation of p70S6K at threonine 421 and serine ... More
Mechanisms of mallory body formation induced by okadaic acid in drug-primed mice.
AuthorsYuan QX, Nagao Y, Gaal K, Hu B, French SW,
JournalExp Mol Pathol
PubMed ID9828150
Drug-primed mice form Mallory bodies in their liver after various types of liver injury such as heat shock, drug refeeding, or ethanol ingestion. However, the mechanisms involved that lead to Mallory body formation after these different treatments are unknown. There may be a common pathway of Mallory body formation that ... More
Hormonal control of reversible translocation of perilipin B to the plasma membrane in primary human adipocytes.
AuthorsAboulaich N, Vener AV, Strålfors P,
JournalJ Biol Chem
PubMed ID16527823
In adipocytes, perilipin coats and protects the central lipid droplet, which stores triacylglycerol. Alternative mRNA splicing gives rise to perilipin A and B. Hormones such as catecholamines and insulin regulate triacylglycerol metabolism through reversible serine phosphorylation of perilipin A. It was recently shown that perilipin was also located in triacylglycerol-synthesizing ... More
Authorsvan Buul JD, Anthony EC, Fernandez-Borja M, Burridge K, Hordijk PL,
JournalJ Biol Chem
PubMed ID15778498
Vascular endothelial-cadherin (VE-cadherin) controls endothelial cell-cell adhesion and preserves endothelial integrity. In order to maintain endothelial barrier function, VE-cadherin function is tightly regulated through mechanisms that involve protein phosphorylation and cytoskeletal dynamics. Here, we show that loss of VE-cadherin function results in intercellular gap formation and a drop in electrical ... More
Investigation of the lateral light-induced migration of photosystem II light-harvesting proteins by nano-high performance liquid chromatography electrospray ionization mass spectrometry.
AuthorsTimperio AM, Zolla L,
JournalJ Biol Chem
PubMed ID15944149
This study reports a detailed analysis of the light-induced lateral migration of the photosystem II (PSII) antennae between appressed and non-appressed thylakoid membranes. The relative PSII antennae that migrated to stroma lamellae were readily established on the basis of peak areas of the separated stroma proteins in the ultraviolet chromatograms. ... More
Phycobilisome linker proteins are phosphorylated in Synechocystis sp. PCC 6803.
AuthorsPiven I, Ajlani G, Sokolenko A,
JournalJ Biol Chem
PubMed ID15805115
The controversial issue of protein phosphorylation from the photosynthetic apparatus of Synechocystis sp. PCC 6803 has been reinvestigated using new detection tools that include various immunological and in vivo labeling approaches. The set of phosphoproteins detected with these methods includes ferredoxin-NADPH reductase and the linker proteins of the phycobilisome antenna. ... More
Activated protein C mediates novel lung endothelial barrier enhancement: role of sphingosine 1-phosphate receptor transactivation.
AuthorsFinigan JH, Dudek SM, Singleton PA, Chiang ET, Jacobson JR, Camp SM, Ye SQ, Garcia JG,
JournalJ Biol Chem
PubMed ID15710622
Increased endothelial cell (EC) permeability is central to the pathophysiology of inflammatory syndromes such as sepsis and acute lung injury (ALI). Activated protein C (APC), a serine protease critically involved in the regulation of coagulation and inflammatory processes, improves sepsis survival through an unknown mechanism. We hypothesized a direct effect ... More
Evidence for an essential catalytic role of the F10 protein kinase in vaccinia virus morphogenesis.
AuthorsSzajner P, Weisberg AS, Moss B,
JournalJ Virol
PubMed ID14671107
Temperature-sensitive mutants of vaccinia virus, with genetic changes that map to the open reading frame encoding the F10 protein kinase, exhibit a defect at an early stage of viral morphogenesis. To further study the role of the enzyme, we constructed recombinant vaccinia virus vF10V5i, which expresses inducible V5 epitope-tagged F10 ... More
Serine phosphorylation of p60 tumor necrosis factor receptor by PKC-delta in TNF-alpha-activated neutrophils.
AuthorsKilpatrick LE, Song YH, Rossi MW, Korchak HM,
JournalAm J Physiol Cell Physiol
PubMed ID11078718
Tumor necrosis factor-alpha (TNF-alpha) triggers degranulation and oxygen radical release in adherent neutrophils. The p60TNF receptor (p60TNFR) is responsible for proinflammatory signaling, and protein kinase C (PKC) is a candidate for the regulation of p60TNFR. Both TNF-alpha and the PKC-activator phorbol 12-myristate 13-acetate triggered phosphorylation of p60TNFR. Receptor phosphorylation was ... More
Bryostatin-1 enhances barrier function in T84 epithelia through PKC-dependent regulation of tight junction proteins.
AuthorsYoo J, Nichols A, Mammen J, Calvo I, Song JC, Worrell RT, Matlin K, Matthews JB,
JournalAm J Physiol Cell Physiol
PubMed ID12660149
Protein kinase C (PKC) is known to regulate epithelial barrier function. However, the effect of specific PKC isozymes, and their mechanism of action, are largely unknown. We determined that the nonphorbol ester PKC agonist bryostatin-1 increased transepithelial electrical resistance (TER), a marker of barrier function, in confluent T84 epithelia. Bryostatin-1, ... More
Regulation of the blood-testis barrier by coxsackievirus and adenovirus receptor.
AuthorsSu L, Mruk DD, Cheng CY,
JournalAm J Physiol Cell Physiol
PubMed ID22875787
The blood-testis barrier (BTB) divides the seminiferous epithelium into the basal and the adluminal compartment. It restricts paracellular diffusion of molecules between Sertoli cells, confers cell polarity, and creates a unique microenvironment in the adluminal compartment for spermatid development. However, it undergoes restructuring during the epithelial cycle so that preleptotene ... More
Brassinosteroids inhibit pathogen-associated molecular pattern-triggered immune signaling independent of the receptor kinase BAK1.
AuthorsAlbrecht C, Boutrot F, Segonzac C, Schwessinger B, Gimenez-Ibanez S, Chinchilla D, Rathjen JP, de Vries SC, Zipfel C
JournalProc Natl Acad Sci U S A
PubMed ID22087006
Plants and animals use innate immunity as a first defense against pathogens, a costly yet necessary tradeoff between growth and immunity. In Arabidopsis, the regulatory leucine-rich repeat receptor-like kinase (LRR-RLK) BAK1 combines with the LRR-RLKs FLS2 and EFR in pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and the LRR-RLK BRI1 in ... More
Monoclonal antibodies to phosphotyrosine.
AuthorsGlenney JR, Zokas L, Kamps MP
JournalJ Immunol Methods
PubMed ID2452204
Phosphotyrosine coupled to KLH, BSA, and OVA was used for the production and screening of antibodies to phosphotyrosine. 800 hybridomas secreting antibodies that bound to phosphotyrosine were detected by ELISA. The most reactive 100 of these 800 were tested subsequently for their ability to bind phosphotyrosine-containing proteins on Western blots. ... More
Protein kinase C? phosphorylates occludin and promotes assembly of epithelial tight junctions.
AuthorsJain S, Suzuki T, Seth A, Samak G, Rao R
JournalBiochem J
PubMed ID21545357
Protein kinases play an important role in the regulation of epithelial tight junctions. In the present study, we investigated the role of PKC? (protein kinase C?) in tight junction regulation in Caco-2 and MDCK (Madin-Darby canine kidney) cell monolayers. Inhibition of PKC? by a specific PKC? pseudosubstrate peptide results in ... More
Identification and subcellular localization of proteins that are rapidly phosphorylated in tyrosine in response to colony-stimulating factor 1.
AuthorsSengupta A, Liu WK, Yeung YG, Yeung DC, Frackelton AR, Stanley ER
JournalProc Natl Acad Sci U S A
PubMed ID2460861
To investigate growth factor-mediated signal transduction, we have studied phosphorylation events that take place within seconds of the binding of colony-stimulating factor 1 (CSF-1) to its cell-surface receptor. CSF-1 stimulated rapid tyrosine phosphorylation of cellular proteins in murine BAC1.2F5 macrophages at 37 degrees C and 4 degrees C. The pattern ... More
Nutrient stimulation results in a rapid Ca2+-dependent threonine phosphorylation of myosin heavy chain in rat pancreatic islets and RINm5F cells.
AuthorsWilson JR, Ludowyke RI, Biden TJ
JournalJ Biol Chem
PubMed ID9712904
Activation of protein kinases plays an important role in the Ca2+-dependent stimulation of insulin secretion by nutrients. The aim of the present study was to identify kinase substrates with the potential to regulate secretion because these have been poorly defined. Nutrient stimulation of the rat insulinoma RINm5F cell line and ... More