Small Signal Stability
Mostrando 25-35 de 35 artigos, teses e dissertações.
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25. Peroxisomes in Saccharomyces cerevisiae: immunofluorescence analysis and import of catalase A into isolated peroxisomes.
To isolate peroxisomes from Saccharomyces cerevisiae of a quality sufficient for in vitro import studies, we optimized the conditions for cell growth and for cell fractionation. Stability of the isolated peroxisomes was monitored by catalase latency and sedimentability of marker enzymes. It was improved by (i) using cells that were shifted to oleic acid medi
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26. MDM2 promotes p21waf1/cip1 proteasomal turnover independently of ubiquitylation
The CDK inhibitor p21waf1/cip1 is degraded by a ubiquitin-independent proteolytic pathway. Here, we show that MDM2 mediates this degradation process. Overexpression of wild-type or ring finger-deleted, but not nuclear localization signal (NLS)-deleted, MDM2 decreased p21waf1/cip1 levels without ubiquitylating this protein and affecting its mRNA level in p53�
Oxford University Press.
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27. The tRNA function of SsrA contributes to controlling repression of bacteriophage Mu prophage
The small regulatory RNA SsrA has both tRNA and mRNA activities. It charges alanine and interacts with stalled ribosomes, allowing for translation to resume on the SsrA mRNA moiety. Hence, unfinished peptides carry a short amino acid tag, which serves as a signal for degradation by energy-dependent proteases. In SsrA-defective Escherichia coli strains, therm
The National Academy of Sciences.
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28. A degradation signal located in the C-terminus of p21WAF1/CIP1 is a binding site for the C8 α-subunit of the 20S proteasome
The cyclin-dependent kinase inhibitor p21WAF1/CIP1 is a key regulator of cell-cycle progression and its expression is tightly regulated at the level of transcription and by proteasome-dependent proteolysis. The turnover of p21WAF1/CIP1 by proteasomes does not always require the ubiquitylation of p21WAF1/CIP1 suggesting that there could be an alternative path
Oxford University Press.
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29. Selective stabilization of microtubules oriented toward the direction of cell migration.
A small subset of the microtubule (MT) array in many cultured cells does not exhibit the rapid turnover (t 1/2 approximately equal to 10 min) shown by most cellular MTs. The function of the stable class of MTs is unknown and has been confounded by the apparent lack of organization of stable MTs within cells. Using an antibody against detyrosinated tubulin, a
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30. A Brome Mosaic Virus Intergenic RNA3 Replication Signal Functions with Viral Replication Protein 1a To Dramatically Stabilize RNA In Vivo
Brome mosaic virus (BMV), a positive-strand RNA virus in the alphavirus-like superfamily, encodes two RNA replication proteins. The 1a protein has putative helicase and RNA-capping domains, whereas 2a contains a polymerase-like domain. Saccharomyces cerevisiae expressing 1a and 2a is capable of replicating a BMV RNA3 template produced by in vivo transcriptio
American Society for Microbiology.
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31. Role of SpoVG in Asymmetric Septation in Bacillus subtilis
Deletion of the citC gene, coding for isocitrate dehydrogenase, arrests sporulation of Bacillus subtilis at stage I after bipolar localization of the cell division protein FtsZ but before formation of the asymmetric septum. A spontaneous extragenic suppressor mutation that overcame the stage I block was found to map within the spoVG gene. The suppressing mut
American Society for Microbiology.
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32. Cloning, phenotypic expression, and DNA sequence of the gene for lactacin F, an antimicrobial peptide produced by Lactobacillus spp.
Lactacin F is a heat-stable bacteriocin produced by Lactobacillus acidophilus 11088. A 63-mer oligonucleotide probe deduced from the N-terminal lactacin F amino acid sequence was used to clone the putative laf structural gene from plasmid DNA of a lactacin F-producing transconjugant, L. acidophilus T143. One clone, NCK360, harbored a recombinant plasmid, pTR
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33. M-phase kinases induce phospho-dependent ubiquitination of somatic Wee1 by SCFβ-TrCP
Wee1, the Cdc2 inhibitory kinase, needs to be down-regulated at the onset of mitosis to ensure rapid activation of Cdc2. Previously, we have shown that human somatic Wee1 (Wee1A) is down-regulated both by protein phosphorylation and degradation, but the underlying mechanisms had not been elucidated. In the present study, we have identified the β-transducin
National Academy of Sciences.
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34. Hepatitis B virus HBx protein activates transcription factor NF-kappaB by acting on multiple cytoplasmic inhibitors of rel-related proteins.
The HBx protein is a small polypeptide encoded by mammalian hepadnaviruses that is essential for viral infectivity and is thought to play a role in development of hepatocellular carcinoma during chronic hepatitis B virus infection. HBx is a transactivator that stimulates Ras signal transduction pathways in the cytoplasm and certain transcription elements in
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35. Viral DNA synthesis in nonpermissive rat F-111 cells and its role in neoplastic transformation by polyomavirus.
We have investigated the occurrence and role of polyomavirus DNA synthesis in neoplastic transformation by this virus. We show that after infection of Fischer rat F-111 cells at 37 degrees C, there is two- to threefold increase in the level of viral DNA as compared with the input signal, with a peak observed between 5 and 7 days postinfection. Viral DNA synt