Trypanosoma brucei: Characterization of a Life Cycle Stage-Specific G-Protein

1995 ◽  
Vol 80 (2) ◽  
pp. 308-318 ◽  
Author(s):  
L.J. Coulter ◽  
G. Hide
Keyword(s):  
Life Cycle ◽  
G Protein ◽  
Trypanosoma Brucei ◽  
Life Cycle Stage

Developmental aspects of uridine addition within mitochondrial transcripts of Trypanosoma brucei

1988 ◽  
Vol 8 (3) ◽  
pp. 1259-1265
Author(s):  
J E Feagin ◽  
K Stuart
Keyword(s):  
Life Cycle ◽  
Cytochrome Oxidase ◽  
Trypanosoma Brucei ◽  
Cytochrome B ◽  
Respiratory System ◽  
Life Cycle Stage ◽  
Stage Specificity ◽  
Life Cycle Stages ◽  
Mitochondrial Transcripts ◽  
Cytochrome Oxidase Ii

The mitochondrial respiratory system is absent in slender bloodstream forms of Trypanosoma brucei, incomplete in stumpy bloodstream forms, and complete in procyclic (insect) forms. The steady-state abundance of transcripts of some mitochondrially encoded components of the respiratory system correlates with its differential expression in different life cycle stages. Recently, it was reported that uridines which are not encoded in the genome are added to cytochrome b and cytochrome oxidase II transcripts. We now report that the (U)+ transcripts of both genes are found in procyclic forms and to some degree in stumpy forms but are absent in slender forms. The uridine additions to cytochrome oxidase II correct a frameshift in the gene and presumably allow production of a full-length protein, whereas those added to cytochrome b create an in-frame AUG which extends the N terminus of the predicted protein by 20 amino acids. The stage specificity of uridine additions to these transcripts thus reflects the life cycle stage during which the protein products would be used. Transcripts of MURF2, a gene of unknown function, have additional uridines in both slender and procyclic forms which create two in-frame AUGs. MURF2 transcripts additionally differ from the DNA sequence in ways which cannot be explained by uridine addition alone, implying that other processes alter these transcripts.

scholarly journals Molecular Identification and Characterization of an Essential Pyruvate Transporter from Trypanosoma brucei

2013 ◽  
Vol 288 (20) ◽  
pp. 14428-14437 ◽  
Author(s):  
Marco A. Sanchez
Keyword(s):  
Trypanosoma Brucei ◽  
Drug Target ◽  
Life Cycle Stage ◽  
Bloodstream Form ◽  
Potential Drug Target ◽  
High Affinity ◽  
Physiological Relevance ◽  
First Time ◽  
Identification And Characterization

Pyruvate export is an essential physiological process for the bloodstream form of Trypanosoma brucei as the parasite would otherwise accumulate this end product of glucose metabolism to toxic levels. In the studies reported here, genetic complementation in Saccharomyces cerevisiae has been employed to identify a gene (TbPT0) that encodes this vital pyruvate transporter from T. brucei. Expression of TbPT0 in S. cerevisiae reveals that TbPT0 is a high affinity pyruvate transporter. TbPT0 belongs to a clustered multigene family consisting of five members, whose expression is up-regulated in the bloodstream form. Interestingly, TbPT family permeases are related to polytopic proteins from plants but not to characterized monocarboxylate transporters from mammals. Remarkably, inhibition of the TbPT gene family expression in bloodstream parasites by RNAi is lethal, confirming the physiological relevance of these transporters. The discovery of TbPT0 reveals for the first time the identity of the essential pyruvate transporter and provides a potential drug target against the mammalian life cycle stage of T. brucei.

Coordination of the Cell Cycle in Trypanosomes

2019 ◽  
Vol 73 (1) ◽  
pp. 133-154 ◽  
Author(s):  
Richard J. Wheeler ◽  
Keith Gull ◽  
Jack D. Sunter
Keyword(s):  
Cell Cycle ◽  
Life Cycle ◽  
Trypanosoma Brucei ◽  
Cross Talk ◽  
Life Cycle Stage ◽  
Life Cycles ◽  
Complex Life Cycles ◽  
Cell Divisions ◽  
Proliferative Cell

Trypanosomes have complex life cycles within which there are both proliferative and differentiation cell divisions. The coordination of the cell cycle to achieve these different divisions is critical for the parasite to infect both host and vector. From studying the regulation of the proliferative cell cycle of the Trypanosoma brucei procyclic life cycle stage, three subcycles emerge that control the duplication and segregation of ( a) the nucleus, ( b) the kinetoplast, and ( c) a set of cytoskeletal structures. We discuss how the clear dependency relationships within these subcycles, and the potential for cross talk between them, are likely required for overall cell cycle coordination. Finally, we look at the implications this interdependence has for proliferative and differentiation divisions through the T. brucei life cycle and in related parasitic trypanosomatid species.

scholarly journals Developmental aspects of uridine addition within mitochondrial transcripts of Trypanosoma brucei.

1988 ◽  
Vol 8 (3) ◽  
pp. 1259-1265 ◽  
Author(s):  
J E Feagin ◽  
K Stuart
Keyword(s):  
Life Cycle ◽  
Cytochrome Oxidase ◽  
Trypanosoma Brucei ◽  
Cytochrome B ◽  
Respiratory System ◽  
Life Cycle Stage ◽  
Stage Specificity ◽  
Life Cycle Stages ◽  
Mitochondrial Transcripts ◽  
Cytochrome Oxidase Ii

The mitochondrial respiratory system is absent in slender bloodstream forms of Trypanosoma brucei, incomplete in stumpy bloodstream forms, and complete in procyclic (insect) forms. The steady-state abundance of transcripts of some mitochondrially encoded components of the respiratory system correlates with its differential expression in different life cycle stages. Recently, it was reported that uridines which are not encoded in the genome are added to cytochrome b and cytochrome oxidase II transcripts. We now report that the (U)+ transcripts of both genes are found in procyclic forms and to some degree in stumpy forms but are absent in slender forms. The uridine additions to cytochrome oxidase II correct a frameshift in the gene and presumably allow production of a full-length protein, whereas those added to cytochrome b create an in-frame AUG which extends the N terminus of the predicted protein by 20 amino acids. The stage specificity of uridine additions to these transcripts thus reflects the life cycle stage during which the protein products would be used. Transcripts of MURF2, a gene of unknown function, have additional uridines in both slender and procyclic forms which create two in-frame AUGs. MURF2 transcripts additionally differ from the DNA sequence in ways which cannot be explained by uridine addition alone, implying that other processes alter these transcripts.

Sign in / Sign up

Export Citation Format

Share Document