Man toTrypanosome: The tubulin tyrosination/detyrosination cycle revisited

Idriss, Haitham T.

doi:10.1002/(sici)1097-0169(200003)45:3<173::aid-cm1>3.0.co;2-o

Cited by 36 publications

(8 citation statements)

References 108 publications

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“…The antibody YL1/2 [specific for a carboxyl‐tyrosinated form of α‐tubulin (21)], proved informative in this regard. In many eukaryotes, α‐tubulin is synthesized with a C‐terminal tyrosine residue, but this tyrosine residue is removed following microtubule assembly (reviewed in 22). As new microtubules are tyrosinated but become progressively detyrosinated over time, YL1/2 is regarded as a specific marker for new microtubules.…”

Section: Resultsmentioning

confidence: 99%

An Essential Quality Control Mechanism at the Eukaryotic Basal Body Prior to Intraflagellar Transport

Stephan

Vaughan

Shaw

et al. 2007

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†These authors contributed equally to this work.Constructing a eukaryotic cilium/flagellum is a demanding task requiring the transport of proteins from their cytoplasmic synthesis site into a spatially and environmentally distinct cellular compartment. The clear potential hazard is that import of aberrant proteins could seriously disable cilia/flagella assembly or turnover processes. Here, we reveal that tubulin protein destined for incorporation into axonemal microtubules interacts with a tubulin cofactor C (TBCC) domain-containing protein that is specifically located at the mature basal body transitional fibres. RNA interference-mediated ablation of this protein results in axonemal microtubule defects but no effect on other microtubule populations within the cell. Bioinformatics analysis indicates that this protein belongs to a clade of flagellum-specific TBCC-like proteins that includes the human protein, XRP2, mutations which lead to certain forms of the hereditary eye disease retinitis pigmentosa. Taken with other observations regarding the role of transitional fibres in cilium/flagellum assembly, we suggest that a localized protein processing capacity embedded at transitional fibres ensures the 'quality' of tubulin imported into the cilium/flagellum, and further, that loss of a ciliary/flagellar quality control capability may underpin a number of human genetic disorders.Key words: basal body, chaperone, flagellum, intraflagellar transport, retinitis pigmentosa, tubulin, tubulin cofactor C, trypanosome Eukaryotic cilia and flagella are evolutionarily conserved organelles that perform a diversity of biological functions, ranging from motility to sensory perception and are vital to human health. Defects in cilium/flagellum function underpin a wide range of inherited human disorders including respiratory disease, retinal degeneration as well as more complex developmental disorders such as Bardet-Biedl syndrome (BBS) and hydrocephalus (1). The construction of a flagellum/cilium, involving assembly of several hundred distinct proteins (2-5), is made more difficult by the fact that in most eukaryotes, assembly occurs in a ribosome-free cellular compartment distinct, and ultimately distant, from the normal cellular cytoplasm (6). This assembly mechanism provides additional challenges and necessitates accurate intracellular targeting, processing and transport of proteins into the cilium/flagellum.With a few exceptions (7,8), cilium/flagellum assembly relies upon an evolutionarily conserved bi-directional transport mechanism known as intraflagellar transport (IFT) (reviewed in 9). Transitional fibres radiating from the mature basal body demarcate the boundary of the cilium/ flagellum compartment and are pivotal to this process acting as both docking sites for IFT motor proteins and regulating entry of IFT particles into the cilium/flagellum (10,11). Molecular understanding of IFT has advanced rapidly in recent years, yet our knowledge of events relating to recruitment and processing of proteins prior to IFT-mediated...

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Section: Resultsmentioning

confidence: 99%

An Essential Quality Control Mechanism at the Eukaryotic Basal Body Prior to Intraflagellar Transport

Stephan

Vaughan

Shaw

et al. 2007

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“…Different post‐translational modifications of tubulin relate to the stability, dynamic, and age of the microtubules (Gundersen et al. 1984; Kreis 1987; Wehland and Weber 1987; MacRae 1997; Idriss 2000; Dent and Gertler 2003; Westermann and Weber 2003). Using modification‐specific antibodies we probed for the presence of post‐translationally modified tubulins in filopodia.…”

Section: Resultsmentioning

confidence: 99%

TRPV1 expression‐dependent initiation and regulation of filopodia

Goswami

Hucho

2007

Journal of Neurochemistry

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Transient receptor potential vanilloid subtype 1 (TRPV1), a non-selective cation channel, is present endogenously in dorsal root ganglia (DRG) neurons. It is involved in the recognition of various pain producing physical and chemical stimuli. In this work, we demonstrate that expression of TRPV1 induces neurite-like structures and filopodia and that the expressed protein is localized at the filopodial tips. Exogenous expression of TRPV1 induces filopodia both in DRG neuron-derived F11 cells and in non-neuronal cells, such as HeLa and human embryonic kidney (HEK) cells. We find that some of the TRPV1 expression-induced filopodia contain microtubules and microtubule-associated components, and establish cell-to-cell extensions. Using live cell microscopy, we demonstrate that the filopodia are responsive to TRPV1-specific ligands. But both, initiation and subsequent cell-to-cell extension formation, is independent of TRPV1 channel activity. The N-terminal intracellular domain of TRPV1 is sufficient for filopodial structure initiation while the C-terminal cytoplasmic domain is involved in the stabilization of microtubules within these structures. In addition, exogenous expression of TRPV1 results in altered cellular distribution and in enhanced endogenous expression of non-conventional myosin motors, namely myosin IIA and myosin IIIA. These data indicate a novel role of TRPV1 in the regulation of cellular morphology and cellular contact formation.

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“…The number of acidic residues in C‐terminal domains of atub and btub from T. vaginalis is very similar to that found in the related species, T. mobilensis. Neither trichomonad α‐tubulin sequence presents a C‐terminal Tyr residue which participates in the detyrosination/tyrosination cycle in some α‐tubulins (for review see Idriss 2000). This involves removal of the C‐terminal Tyr from newly synthesized α‐tubulin by a specific carboxypeptidase, after which a tubulin‐tyrosine ligase (TTL) restores the C‐terminal Tyr of α‐tubulin that had previously been detyrosinated (Chang and Flavin 1988).…”

Section: Resultsmentioning

confidence: 99%

Tubulins in Trichomonas vaginalis: Molecular Characterization of α‐Tubulin Genes, Posttranslational Modifications, and Homology Modeling of the Tubulin Dimer

Noël

Gerbod

Fast

et al. 2001

J Eukaryotic Microbiology

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We have isolated and analysed an alpha-tubulin-encoding gene (atub1) in an early-diverging eukaryote, Trichomonas vaginalis. The complete atub1 open reading frame included 1.356 bp encoding a polypeptide of 452 amino-acyl residues. A second alpha-tubulin gene (atub2) was amplified by PCR using primers derived from consensus alpha-tubulin amino acid sequences. Both T. vaginalis alpha-tubulin sequences showed high identity to those described in other parabasalids (94.4%-97.3%), and exhibited a high degree of similarity to sequences from Metazoa (such as pig brain) and diplomonads (such as Giardia). Despite large evolutionary distances previously observed between trichomonads and mammals, the three-dimensional model of the T. vaginalis tubulin dimer was very similar to that of pig brain. Possible correlations between alpha-tubulin sequences and posttranslational modifications (PTMs) were examined. Our observations corroborated previous data obtained in T. vaginalis using specific anti-PTMs antibodies. As described in the related species Tritrichomonas mobilensis, microtubules are likely acetylated, non-tyrosinated, glutamylated, and non-glycylated in T. vaginalis. Evolutionary considerations concerning the time of appearance of these tubulin PTMs are also discussed since trichomonads are potentially one of the earliest diverging eukaryotic lineages.

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Man toTrypanosome: The tubulin tyrosination/detyrosination cycle revisited

Cited by 36 publications

References 108 publications

An Essential Quality Control Mechanism at the Eukaryotic Basal Body Prior to Intraflagellar Transport

An Essential Quality Control Mechanism at the Eukaryotic Basal Body Prior to Intraflagellar Transport

TRPV1 expression‐dependent initiation and regulation of filopodia

Tubulins in Trichomonas vaginalis: Molecular Characterization of α‐Tubulin Genes, Posttranslational Modifications, and Homology Modeling of the Tubulin Dimer

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