scholarly journals The PARP Promoter of Trypanosoma Brucei Is Developmentally Regulated in a Chromosomal Context

1996 ◽  
Vol 24 (7) ◽  
pp. 1202-1211 ◽  
Author(s):  
S. Biebinger ◽  
S. Rettenmaier ◽  
J. Flaspohler ◽  
C. Hartmann ◽  
J. Pena-Diaz ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Developmentally Regulated

Pseudouridines on Trypanosoma brucei mRNAs are developmentally regulated: implications to mRNA stability and protein binding

2021 ◽  
Author(s):  
K. Shanmugha Rajan ◽  
Kathy Adler ◽  
Hava Madmoni ◽  
Dana Chen ◽  
Smadar Cohen‐Chalamish ◽  
...  
Keyword(s):  
Protein Binding ◽  
Trypanosoma Brucei ◽  
Mrna Stability ◽  
Developmentally Regulated

Posttranscriptional regulation of cytochrome c expression during the developmental cycle of Trypanosoma brucei

1988 ◽  
Vol 8 (11) ◽  
pp. 4625-4633
Author(s):  
A F Torri ◽  
S L Hajduk
Keyword(s):  
Steady State ◽  
Cytochrome C ◽  
Trypanosoma Brucei ◽  
Posttranscriptional Regulation ◽  
Mitochondrial Protein ◽  
Developmental Cycle ◽  
Mrna Levels ◽  
Developmentally Regulated ◽  
Partial Cdna ◽  
Steady State Levels

We examined the expression of a nucleus-encoded mitochondrial protein, cytochrome c, during the life cycle of Trypanosoma brucei. The bloodstream forms of T. brucei, the long slender and short stumpy trypanosomes, have inactive mitochondria with no detectable cytochrome-mediated respiration. The insect form of T. brucei, the procyclic trypanosomes, has fully functional mitochondria. Cytochrome c is spectrally undetectable in the bloodstream forms of trypanosomes, but during differentiation to the procyclic form, spectrally detected holo-cytochrome c accumulates rapidly. We have purified T. brucei cytochrome c and raised antibodies that react to both holo- and apo-cytochrome c. In addition, we isolated a partial cDNA to trypanosome cytochrome c. An examination of protein expression and steady-state mRNA levels in T. brucei indicated that bloodstream trypanosomes did not express cytochrome c but maintained significant steady-state levels of cytochrome c mRNA. The results suggest that in T. brucei, cytochrome c is developmentally regulated by a posttranscriptional mechanism which prevents either translation or accumulation of cytochrome c in the bloodstream trypanosomes.

Developmental regulation of a novel repetitive protein of Trypanosoma brucei

1987 ◽  
Vol 7 (8) ◽  
pp. 2838-2844
Author(s):  
M R Mowatt ◽  
C E Clayton
Keyword(s):  
Trypanosoma Brucei ◽  
Tandem Repeats ◽  
Signal Sequence ◽  
Developmental Regulation ◽  
Developmentally Regulated ◽  
Hydrophobic Domain ◽  
Reading Frame ◽  
Amino Terminal ◽  
Membrane Bound

Trypanosoma brucei undergoes many morphological and biochemical changes during transformation from the bloodstream trypomastigote to the insect procyclic trypomastigote form. We cloned and determined the complete nucleotide sequence of a developmentally regulated cDNA. The corresponding mRNA was abundant in in vitro-cultivated procyclics but absent in bloodstream forms. The trypanosome genome contains eight genes homologous to this cDNA, arranged as four unlinked pairs of tandem repeats. The longest open reading frame of the cDNA predicts a protein of 15 kilodaltons, the central portion of which consists of 29 tandem glutamate-proline dipeptides. The repetitive region is preceded by an amino-terminal signal sequence and followed by a hydrophobic domain that could serve as a membrane anchor; the mRNA was found on membrane-bound polyribosomes. These results suggest that the protein is membrane associated.

Developmentally regulated trafficking of the lysosomal membrane protein p67 in Trypanosoma brucei

2002 ◽  
Vol 115 (16) ◽  
pp. 3253-3263 ◽  
Author(s):  
David L. Alexander ◽  
Kevin J. Schwartz ◽  
Andrew E. Balber ◽  
James D. Bangs
Keyword(s):  
Cell Surface ◽  
Trypanosoma Brucei ◽  
Membrane Glycoprotein ◽  
Type I ◽  
Developmentally Regulated ◽  
Lysosomal Membrane Protein ◽  
Targeting Signals ◽  
Lysosomal Targeting ◽  
Endocytic Activity ◽  
Regulated Trafficking

p67 is a lysosomal type I membrane glycoprotein of Trypanosoma brucei. In procyclic stage cells p67 trafficks to the lysosome without modification, but in the bloodstream stage Golgi processing adds poly-N-acetyllactosamine to N-glycans. In both stages proteolytic fragmentation occurs in the lysosome, but turnover is approximately nine times faster in bloodstream cells. Trafficking of wildtype p67 and mutants missing the cytoplasmic (p67ΔCD) or cytoplasmic/transmembrane domains (p67ΔTM) was monitored by pulse-chase,surface biotinylation and immunofluorescence. Overexpressed wildtype p67 trafficks normally in procyclics, but some leaks to the cell surface suggesting that the targeting machinery is saturable. p67ΔCD and p67ΔTM are delivered to the cell surface and secreted, respectively. The membrane/cytoplasmic domains function correctly in procyclic cells when fused to GFP indicating that these domains are sufficient for stage-specific lysosomal targeting. In contrast, p67 wildtype and deletion reporters are overwhelmingly targeted to the lysosome and degraded in bloodstream cells. These findings suggest that either redundant developmentally regulated targeting signals/machinery are operative in this stage or that the increased endocytic activity of bloodstream cells prevents export of the deletion reporters.

scholarly journals Developmentally Regulated Novel Non-coding Anti-sense Regulators of mRNA Translation in Trypanosoma brucei

iScience ◽  
2020 ◽  
Vol 23 (12) ◽  
pp. 101780
Author(s):  
K. Shanmugha Rajan ◽  
Tirza Doniger ◽  
Smadar Cohen-Chalamish ◽  
Praveenkumar Rengaraj ◽  
Beathrice Galili ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Mrna Translation ◽  
Developmentally Regulated

scholarly journals Variation of tandem repeats in the developmentally regulated procyclic acidic repetitive proteins of Trypanosoma brucei.

1989 ◽  
Vol 9 (3) ◽  
pp. 1332-1335 ◽  
Author(s):  
M R Mowatt ◽  
G S Wisdom ◽  
C E Clayton
Keyword(s):  
Gene Family ◽  
Trypanosoma Brucei ◽  
Tandem Repeats ◽  
Surface Proteins ◽  
Northern Hybridization ◽  
Developmentally Regulated ◽  
Coordinate Regulation ◽  
Polymorphic Genes ◽  
Alpha Gene ◽  
Carboxy Terminal

The procyclic acidic repetitive proteins (PARPs) of Trypanosoma brucei are developmentally regulated surface proteins encoded by a family of polymorphic genes. We have determined the complete nucleotide sequence of a novel member of the PARP gene family and investigated its expression. The amino acid sequence deduced from the parpA alpha gene showed a marked conservation of both the amino- and carboxy-terminal regions compared with other PARPs but revealed the substitution of a pentapeptide for the dipeptide repeating unit that is characteristic of all other PARPs. Northern hybridization analysis indicated that expression of the parpA alpha gene, like that of other members of this gene family, is confined to the procyclic stage of the T. brucei life cycle. This result implies coordinate regulation of the unlinked genetic loci that encode PARPs.

TbRAB18, a developmentally regulated Golgi GTPase from Trypanosoma brucei

2002 ◽  
Vol 121 (1) ◽  
pp. 63-74 ◽  
Author(s):  
Tim R Jeffries ◽  
Gareth W Morgan ◽  
Mark C Field
Keyword(s):  
Trypanosoma Brucei ◽  
Developmentally Regulated

scholarly journals Developmental regulation of edited CYb and COIII mitochondrial mRNAs is achieved by distinct mechanisms in Trypanosoma brucei

2020 ◽  
Vol 48 (15) ◽  
pp. 8704-8723
Author(s):  
Joseph T Smith Jr. ◽  
Eva Doleželová ◽  
Brianna Tylec ◽  
Jonathan E Bard ◽  
Runpu Chen ◽  
...  
Keyword(s):  
Life Cycle ◽  
Trypanosoma Brucei ◽  
High Throughput Sequencing ◽  
Environmental Changes ◽  
Developmental Regulation ◽  
Complex Life Cycle ◽  
Mrna Levels ◽  
Developmentally Regulated ◽  
Life Cycle Stages

Abstract Trypanosoma brucei is a parasitic protozoan that undergoes a complex life cycle involving insect and mammalian hosts that present dramatically different nutritional environments. Mitochondrial metabolism and gene expression are highly regulated to accommodate these environmental changes, including regulation of mRNAs that require extensive uridine insertion/deletion (U-indel) editing for their maturation. Here, we use high throughput sequencing and a method for promoting life cycle changes in vitro to assess the mechanisms and timing of developmentally regulated edited mRNA expression. We show that edited CYb mRNA is downregulated in mammalian bloodstream forms (BSF) at the level of editing initiation and/or edited mRNA stability. In contrast, edited COIII mRNAs are depleted in BSF by inhibition of editing progression. We identify cell line-specific differences in the mechanisms abrogating COIII mRNA editing, including the possible utilization of terminator gRNAs that preclude the 3′ to 5′ progression of editing. By examining the developmental timing of altered mitochondrial mRNA levels, we also reveal transcript-specific developmental checkpoints in epimastigote (EMF), metacyclic (MCF), and BSF. These studies represent the first analysis of the mechanisms governing edited mRNA levels during T. brucei development and the first to interrogate U-indel editing in EMF and MCF life cycle stages.

Transcription of the procyclic acidic repetitive protein genes of Trypanosoma brucei

1990 ◽  
Vol 10 (6) ◽  
pp. 3036-3047
Author(s):  
C E Clayton ◽  
J P Fueri ◽  
J E Itzhaki ◽  
V Bellofatto ◽  
D R Sherman ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Chloramphenicol Acetyltransferase ◽  
Surface Proteins ◽  
Base Pairs ◽  
Developmentally Regulated ◽  
Putative Promoter Region ◽  
Transcriptional Initiation ◽  
Chloramphenicol Acetyltransferase Gene ◽  
Alpha Amanitin ◽  
Repetitive Protein

The procyclic acidic repetitive protein (parp) genes of Trypanosoma brucei encode a small family of abundant surface proteins whose expression is restricted to the procyclic form of the parasite. They are found at two unlinked loci, parpA and parpB; transcription of both loci is developmentally regulated. The region of homology upstream of the A and B parp genes is only 640 base pairs long and may contain sequences responsible for transcriptional initiation and regulation. Transcription upstream of this putative promoter region is not developmentally regulated and is much less active than that of the parp genes; the polymerase responsible is inhibited by alpha-amanitin, whereas that transcribing the parp genes is not. Transcription of the parp genes is strongly stimulated by low levels of UV irradiation. The putative parp promoter, when placed upstream of the chloramphenicol acetyltransferase gene, is sufficient to cause production of chloramphenicol acetyltransferase in a T. brucei DNA transformation assay. Taken together, these results suggest that a promoter for an alpha-amanitin-resistant RNA polymerase lies less than 600 nucleotides upstream of the parp genes.

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