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  • Poster presentation
  • Open Access

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

  • 1, 2Email author,
  • 1, 2, 3,
  • 1, 2,
  • 1, 2,
  • 2,
  • 1, 2,
  • 1, 2 and
  • 1, 2
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