scholarly journals Cloning and characterization of hELD/OSA1, a novel BRG1 interacting protein

2002 ◽  
Vol 364 (1) ◽  
pp. 255-264 ◽  
Author(s):  
Adam F.L. HURLSTONE ◽  
Ivan A. OLAVE ◽  
Nick BARKER ◽  
Mascha van NOORT ◽  
Hans CLEVERS

A highly conserved multisubunit enzymic complex, SWI/SNF, participates in the regulation of eukaryote gene expression through its ability to remodel chromatin. While a single component of SWI/SNF, Swi2 or a related protein, can perform this function in vitro, the other components appear to modulate the activity and specificity of the complex in vivo. Here we describe the cloning of hELD/OSA1, a 189KDa human homologue of Drosophila Eld/Osa protein, a constituent of Drosophila SWI/SNF. By comparing conserved peptide sequences in Eld/Osa homologues we define three domains common to all family members. A putative DNA binding domain, or ARID (AT-rich DNA-interacting domain), may function in targetting SWI/SNF to chromatin. Two other domains unique to Eld/Osa proteins, EHD1 and EHD2, map to the C-teminus. We show that EHD2 mediates binding to Brahma-related gene 1 (BRG1), a human homologue of yeast Swi2. EHD1 and EHD2 also appear capable of interacting with each other. Using an antibody raised against EHD2 of hELD/OSA1, we detected Eld/Osa1 in endogenous SWI/SNF complexes derived from mouse brain.

Development ◽  
1999 ◽  
Vol 126 (6) ◽  
pp. 1259-1268 ◽  
Author(s):  
A. Meng ◽  
B. Moore ◽  
H. Tang ◽  
B. Yuan ◽  
S. Lin

The Drosophila doublesex (dsx) gene encodes a transcription factor that mediates sex determination. We describe the characterization of a novel zebrafish zinc-finger gene, terra, which contains a DNA binding domain similar to that of the Drosophila dsx gene. However, unlike dsx, terra is transiently expressed in the presomitic mesoderm and newly formed somites. Expression of terra in presomitic mesoderm is restricted to cells that lack expression of MyoD. In vivo, terra expression is reduced by hedgehog but enhanced by BMP signals. Overexpression of terra induces rapid apoptosis both in vitro and in vivo, suggesting that a tight regulation of terra expression is required during embryogenesis. Terra has both human and mouse homologs and is specifically expressed in mouse somites. Taken together, our findings suggest that terra is a highly conserved protein that plays specific roles in early somitogenesis of vertebrates.


Author(s):  
Ammad Khan ◽  
Takashi Shimokawa ◽  
Staffan Strömblad ◽  
Hongquan Zhang

AbstractKindlin-2 is a recently identified FERM and PH domain containing integrin interacting protein. Kindlin-2 is ubiquitously expressed in normal tissues. So far, much effort has been spent exploring the functional aspects of Kindlin-2. However, the transcriptional regulation of Kindlin-2 has not yet been investigated. In this study we identified and functionally characterized the promoter of the human Kindlin-2 gene. We show that the core promoter of Kindlin-2 is a 39 base pair long GC rich fragment located −122/-83 upstream of the Kindlin-2 transcription start site. Functional characterization of this core promoter region by both in silico as well as in vitro/in vivo analysis shows that the transcription factor SP1 plays an important role in regulation of Kindlin-2 expression.


2000 ◽  
Vol 74 (8) ◽  
pp. 3682-3695 ◽  
Author(s):  
Paula Traktman ◽  
Ke Liu ◽  
Joseph DeMasi ◽  
Robert Rollins ◽  
Sophy Jesty ◽  
...  

ABSTRACT We have previously reported the construction and characterization of vindH1, an inducible recombinant in which expression of the vaccinia virus H1 phosphatase is regulated experimentally by IPTG (isopropyl-β-d-thiogalactopyranoside) (35). In the absence of H1 expression, the transcriptional competence and infectivity of nascent virions are severely compromised. We have sought to identify H1 substrates by characterizing proteins that are hyperphosphorylated in H1-deficient virions. Here, we demonstrate that the A14 protein, a component of the virion membrane, is indeed an H1 phosphatase substrate in vivo and in vitro. A14 is hyperphosphorylated on serine residues in the absence of H1 expression. To enable a genetic analysis of A14's function during the viral life cycle, we have adopted the regulatory components of the tetracycline (TET) operon and created new reagents for the construction of TET-inducible vaccinia virus recombinants. In the context of a virus expressing the TET repressor (tetR), insertion of the TET operator between the transcriptional and translational start sites of a late viral gene enables its expression to be tightly regulated by TET. We constructed a TET-inducible recombinant for the A14 gene, vindA14. In the absence of TET, vindA14 fails to form plaques and the 24-h yield of infectious progeny is reduced by 3 orders of magnitude. The infection arrests early during viral morphogenesis, with the accumulation of large numbers of vesicles and the appearance of “empty” crescents that appear to adhere only loosely to virosomes. This phenotype corresponds closely to that observed for an IPTG-inducible A14 recombinant whose construction and characterization were reported while our work was ongoing (47). The consistency in the phenotypes seen for the IPTG- and TET-inducible recombinants confirms the efficacy of the TET-inducible system and reinforces the value of having a second, independent system available for generating inducible recombinants.


2019 ◽  
Vol 63 (9) ◽  
Author(s):  
Yu Yamashita ◽  
Kentaro Nagaoka ◽  
Hiroki Kimura ◽  
Masaru Suzuki ◽  
Satoshi Konno ◽  
...  

ABSTRACT The use of macrolides against pneumonia has been reported to improve survival; however, little is known about their efficacy against methicillin-resistant Staphylococcus aureus (MRSA) pneumonia. In this study, we investigated the effect of azithromycin (AZM) and compared it with that of vancomycin (VCM) and daptomycin (DAP) in a murine model of MRSA pneumonia. Mice were infected with MRSA by intratracheal injection and then treated with AZM, VCM, or DAP. The therapeutic effect of AZM, in combination or not with the other drugs, was compared in vivo, whereas the effect of AZM on MRSA growth and toxin mRNA expression was evaluated in vitro. In vivo, the AZM-treated group showed significantly longer survival and fewer bacteria in the lungs 24 h after infection than the untreated group, as well as the other anti-MRSA drug groups. No significant decrease in cytokine levels (interleukin-6 [IL-6] and macrophage inflammatory protein-2 [MIP-2]) in bronchoalveolar lavage fluid or toxin expression levels (α-hemolysin [Hla] and staphylococcal protein A [Spa]) was observed following AZM treatment. In vitro, AZM suppressed the growth of MRSA in late log phase but not in stationary phase. No suppressive effect against toxin production was observed following AZM treatment in vitro. In conclusion, contrary to the situation in vitro, AZM was effective against MRSA growth in vivo in our pneumonia model, substantially improving survival. The suppressive effect on MRSA growth at the initial stage of pneumonia could underlie the potential mechanism of AZM action against MRSA pneumonia.


1996 ◽  
Vol 16 (1) ◽  
pp. 105-114 ◽  
Author(s):  
M T Diaz-Meco ◽  
M M Municio ◽  
P Sanchez ◽  
J Lozano ◽  
J Moscat

The members of the atypical subfamily of protein kinase C (PKC) show dramatic structural and functional differences from other PKC isotypes. Thus, in contrast to the classical or novel PKCs, they are not activated by diacylglycerol or phorbol esters. However, the atypical PKCs are the target of important lipid second messengers such as ceramide, phosphatidic acid, and 3'-phosphoinositides. The catalytic and pseudosubstrate sequences in the two atypical PKCs (lambda/iota PKC and zeta PKC) are identical but are significantly different from those of conventional or novel PKCs. It has been shown that microinjection of a peptide with the sequence of the pseudosubstrate of the atypical PKC isotypes but not of alpha PKC or epsilon PKC dramatically inhibited maturation and NF-kappa B activation in Xenopus oocytes, as well as reinitiation of DNA synthesis in quiescent mouse fibroblasts. This indicates that either or both atypical isoforms are important in cell signalling. Besides the pseudosubstrate, the major differences in the sequence between lambda/iota PKC and zeta PKC are located in the regulatory domain. Therefore, any functional divergence between the two types of atypical PKCs will presumably reside in that region. We report here the molecular characterization of lambda-interacting protein (LIP), a novel protein that specifically interacts with the zinc finger of lambda/iota PKC but not zeta PKC. We show in this paper that this interaction is detected not only in vitro but also in vivo, that LIP activates lambda/iota PKC but not zeta PKC in vitro and in vivo, and that this interaction is functionally relevant. Thus, expression of LIP leads to the transactivation of a kappa B-dependent promoter in a manner that is dependent on lambda/iota PKC. To our knowledge, this is the first report on the cloning and characterization of a protein activator of a PKC that binds to the zinc finger domain, which has so far been considered a site for binding of lipid modulators. The fact that LIP binds to lambda/iota PKC but not to the highly related zeta PKC isoform suggests that the specificity of the activation of the members of the different PKC subfamilies will most probably be accounted for by proteins like LIP rather than by lipid activators.


2000 ◽  
Vol 20 (4) ◽  
pp. 1254-1262 ◽  
Author(s):  
Thomas Caspari ◽  
Maria Dahlen ◽  
Gunilla Kanter-Smoler ◽  
Howard D. Lindsay ◽  
Kay Hofmann ◽  
...  

ABSTRACT Hus1 is one of six checkpoint Rad proteins required for allSchizosaccharomyces pombe DNA integrity checkpoints. MYC-tagged Hus1 reveals four discrete forms. The main form, Hus1-B, participates in a protein complex with Rad9 and Rad1, consistent with reports that Rad1-Hus1 immunoprecipitation is dependent on the rad9 + locus. A small proportion of Hus1-B is intrinsically phosphorylated in undamaged cells and more becomes phosphorylated after irradiation. Hus1-B phosphorylation is not increased in cells blocked in early S phase with hydroxyurea unless exposure is prolonged. The Rad1–Rad9–Hus1-B complex is readily detectable, but upon cofractionation of soluble extracts, the majority of each protein is not present in this complex. Indirect immunofluorescence demonstrates that Hus1 is nuclear and that this localization depends on Rad17. We show that Rad17 defines a distinct protein complex in soluble extracts that is separate from Rad1, Rad9, and Hus1. However, two-hybrid interaction, in vitro association and in vivo overexpression experiments suggest a transient interaction between Rad1 and Rad17.


1973 ◽  
Vol 29 (02) ◽  
pp. 490-498 ◽  
Author(s):  
Hiroh Yamazaki ◽  
Itsuro Kobayashi ◽  
Tadahiro Sano ◽  
Takio Shimamoto

SummaryThe authors previously reported a transient decrease in adhesive platelet count and an enhancement of blood coagulability after administration of a small amount of adrenaline (0.1-1 µg per Kg, i. v.) in man and rabbit. In such circumstances, the sensitivity of platelets to aggregation induced by ADP was studied by an optical density method. Five minutes after i. v. injection of 1 µg per Kg of adrenaline in 10 rabbits, intensity of platelet aggregation increased to 115.1 ± 4.9% (mean ± S. E.) by 10∼5 molar, 121.8 ± 7.8% by 3 × 10-6 molar and 129.4 ± 12.8% of the value before the injection by 10”6 molar ADP. The difference was statistically significant (P<0.01-0.05). The above change was not observed in each group of rabbits injected with saline, 1 µg per Kg of 1-noradrenaline or 0.1 and 10 µg per Kg of adrenaline. Also, it was prevented by oral administration of 10 mg per Kg of phenoxybenzamine or propranolol or aspirin or pyridinolcarbamate 3 hours before the challenge. On the other hand, the enhancement of ADP-induced platelet aggregation was not observed in vitro, when 10-5 or 3 × 10-6 molar and 129.4 ± 12.8% of the value before 10∼6 molar ADP was added to citrated platelet rich plasma (CPRP) of rabbit after incubation at 37°C for 30 second with 0.01, 0.1, 1, 10 or 100 µg per ml of adrenaline or noradrenaline. These results suggest an important interaction between endothelial surface and platelets in connection with the enhancement of ADP-induced platelet aggregation by adrenaline in vivo.


2019 ◽  
Author(s):  
Priya Prakash ◽  
Travis Lantz ◽  
Krupal P. Jethava ◽  
Gaurav Chopra

Amyloid plaques found in the brains of Alzheimer’s disease (AD) patients primarily consists of amyloid beta 1-42 (Ab42). Commercially, Ab42 is synthetized using peptide synthesizers. We describe a robust methodology for expression of recombinant human Ab(M1-42) in Rosetta(DE3)pLysS and BL21(DE3)pLysS competent E. coli with refined and rapid analytical purification techniques. The peptide is isolated and purified from the transformed cells using an optimized set-up for reverse-phase HPLC protocol, using commonly available C18 columns, yielding high amounts of peptide (~15-20 mg per 1 L culture) in a short time. The recombinant Ab(M1-42) forms characteristic aggregates similar to synthetic Ab42 aggregates as verified by western blots and atomic force microscopy to warrant future biological use. Our rapid, refined, and robust technique to purify human Ab(M1-42) can be used to synthesize chemical probes for several downstream in vitro and in vivo assays to facilitate AD research.


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