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 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

scholarly journals Additive and Transcript-Specific Effects of KPAP1 and TbRND Activities on 3′ Non-Encoded Tail Characteristics and mRNA Stability in Trypanosoma brucei

PLoS ONE ◽  
2012 ◽  
Vol 7 (5) ◽  
pp. e37639 ◽  
Author(s):  
Sara L. Zimmer ◽  
Sarah M. McEvoy ◽  
Sarita Menon ◽  
Laurie K. Read
Keyword(s):  
Trypanosoma Brucei ◽  
Mrna Stability ◽  
Specific Effects

scholarly journals Poly(A) binding KPAF4/5 complex stabilizes kinetoplast mRNAs in Trypanosoma brucei

2020 ◽  
Vol 48 (15) ◽  
pp. 8645-8662
Author(s):  
Inna Aphasizheva ◽  
Tian Yu ◽  
Takuma Suematsu ◽  
Qiushi Liu ◽  
Mikhail V Mesitov ◽  
...  
Keyword(s):  
Quality Control ◽  
Trypanosoma Brucei ◽  
Mrna Stability ◽  
Critical Element ◽  
Pentatricopeptide Repeat ◽  
Present Evidence ◽  
Mrna Stabilization ◽  
Translational Activation ◽  
Pyrophosphate Hydrolysis ◽  
Editing Process

Abstract In Trypanosoma brucei, mitochondrial pre-mRNAs undergo 3′-5′ exonucleolytic processing, 3′ adenylation and uridylation, 5′ pyrophosphate removal, and, often, U-insertion/deletion editing. The 3′ modifications are modulated by pentatricopeptide repeat (PPR) Kinetoplast Polyadenylation Factors (KPAFs). We have shown that KPAF3 binding to the 3′ region stabilizes properly trimmed transcripts and stimulates their A-tailing by KPAP1 poly(A) polymerase. Conversely, poly(A) binding KPAF4 shields the nascent A-tail from uridylation and decay thereby protecting pre-mRNA upon KPAF3 displacement by editing. While editing concludes in the 5′ region, KPAF1/2 dimer induces A/U-tailing to activate translation. Remarkably, 5′ end recognition and pyrophosphate hydrolysis by the PPsome complex also contribute to mRNA stabilization. Here, we demonstrate that KPAF4 functions as a heterodimer with KPAF5, a protein lacking discernable motifs. We show that KPAF5 stabilizes KPAF4 to enable poly(A) tail recognition, which likely leads to mRNA stabilization during the editing process and impedes spontaneous translational activation of partially-edited transcripts. Thus, KPAF4/5 represents a poly(A) binding element of the mitochondrial polyadenylation complex. We present evidence that RNA editing substrate binding complex bridges the 5′ end-bound PPsome and 3′ end-bound polyadenylation complexes. This interaction may enable mRNA circularization, an apparently critical element of mitochondrial mRNA stability and quality control.

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