Document Detail


Differentiation of Trypanosoma brucei may be stage non-specific and does not require progression of cell cycle.
MedLine Citation:
PMID:  12823826     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Ubiquitination and proteasomal degradation of cell cycle regulatory proteins are known to play a pivotal role in controlling the progression of the eukaryotic cell cycle. Using the technique of RNA interference (RNAi) on the bloodstream form of Trypanosoma brucei, we were able to knock down expression of each of the 11 non-ATPase regulatory subunit proteins (Rpns) in the 19S regulatory complex of the 26S proteasome. In each case, the knock-down led to arrest of cells within the G1 and G2 phases, suggesting blockage of cell cycle progression at both G1/S and G2/M boundaries. This finding differs from that observed previously in the procyclic form of T. brucei, in which loss of individual Rpns blocks only passage across the G2/M boundary. Thus, proteasomal degradation of additional regulatory protein(s) may be required for exiting from G1 phase in the bloodstream form. In vitro differentiation of each of the 11 Rpn-depleted bloodstream form cell lines into the procyclic form was monitored. Each cell line proceeded to completion of the differentiation process like the wild-type cells with the total percentage of differentiated cells about equivalent to the sum of G1 and G2 cells. Thus, cells trapped in either G1 or G2 phase can apparently still enter and complete the process of differentiation, which is probably neither stage specific nor dependent on the progression of the T. brucei cell cycle. The process is probably a simple pattern change of gene expression in the trypanosome induced by a temperature decrease from 37 degrees C to 26 degrees C in the presence of citrate and cis-aconitate.
Authors:
Yan Li; Ziyin Li; Ching C Wang
Related Documents :
8759936 - Zinc deficiency affects cell cycle and deoxythymidine kinase gene expression in hut-78 ...
6353166 - Cyclic variations in sensitivity to x-irradiation during meiosis in saccharomyces cerev...
14698046 - Cell cycle arrest and autoschizis in a human bladder carcinoma cell line following vita...
11788766 - Differential effect of jasmonic acid and abscisic acid on cell cycle progression in tob...
8856496 - V-src induces constitutive macropinocytosis in rat fibroblasts.
17825296 - The sterol transporting heterodimer abcg5/abcg8 requires bile salts to mediate choleste...
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Molecular microbiology     Volume:  49     ISSN:  0950-382X     ISO Abbreviation:  Mol. Microbiol.     Publication Date:  2003 Jul 
Date Detail:
Created Date:  2003-06-25     Completed Date:  2004-03-04     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  8712028     Medline TA:  Mol Microbiol     Country:  England    
Other Details:
Languages:  eng     Pagination:  251-65     Citation Subset:  IM    
Affiliation:
Department of Pharmaceutical Chemistry, University of California, Genentech Hall, 600 16th Street, San Francisco, CA 94143-2280, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Cell Cycle / physiology*
Proteins / genetics,  metabolism
Protozoan Proteins / genetics,  metabolism
RNA Interference
RNA, Protozoan
Temperature
Trypanosoma brucei brucei / cytology,  genetics,  growth & development,  physiology*
Grant Support
ID/Acronym/Agency:
AI-21786/AI/NIAID NIH HHS
Chemical
Reg. No./Substance:
0/Proteins; 0/Protozoan Proteins; 0/RNA, Protozoan; 0/Rpn1 protein, Trypanosoma

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Species specificity in the activation of Xer recombination at dif by FtsK.
Next Document:  Dipteran predators of Simuliid blackflies: a worldwide review.