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  • Open Access

TbSAXO is a MAP6-related protein involved in motility of Trypanosoma brucei flagellum

  • 1, 2Email author,
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Cilia20121 (Suppl 1) :P16

  • Published:


  • Polypeptide
  • Potential Role
  • Developmental Biology
  • MAP6 Protein
  • Tissue Cell

The microtubules (MTs) of most vertebrate tissue cells will disassemble at low temperature, but some remain cold-stable or resistant to drugs such as nocodazole. It has been shown that MT cold- and nocodazole-resistance is largely due to the association with the class of Microtubule Associated Proteins (MAP) known as MAP6 (previously named STOP for Stable Tubule Only Polypeptide) [1]. MAP6 proteins are expressed only in vertebrates, and have been localized in neurons, astrocytes, oligodendrocytes, fibroblasts, and several tissues. In eukaryotes, the MT-based organelles centrioles, cilia and flagella MT have cold-resistant MTs, but, so far, MAP6 proteins have not been characterized in these organelles. We have recently identified TbSAXO (for Stop AXOneme), a novel flagellar protein in the protozoan parasite Trypanosoma brucei. We show here that TbSAXO is a microtubule stabilizing protein with properties similar, upon cold and nocodazole treatment, to those of the microtubule-stabilizing Mn domains of the MAP6 proteins, thus identifying the first MAP6-related protein in a protozoan. Further, we demonstrate, in the parasite, that TbSAXO is an axoneme-associated protein, which plays a role in flagellum motility. We also show that TbSAXO is the first member of a group of MAP6-related proteins (that we named SAXO proteins) present only in organisms with centrioles / cilia / flagella and ranging from protozoa to mammals, suggesting potential roles of the SAXO proteins in cilia and flagella function.

Authors’ Affiliations

CNRS, Microbiologie Fondamentale et Pathogenicite, UMR-5234, France
University of Bordeaux, Microbiologie Fondamentale et Pathogenicite, UMR-5234, France
Institut Polytechnique de Bordeaux, Microbiologie Fondamentale et Pathogenicite, UMR-5234, France


  1. Bosc C, Andrieux A, Job D: STOP proteins. Biochemistry. 2003, 42: 12125-12132. 10.1021/bi0352163.View ArticlePubMedGoogle Scholar


© Bonhivers et al; licensee BioMed Central Ltd. 2012

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.