title: The small ubiquitin-like modifier (SUMO) is essential in cell cycle regulation in Trypanosoma brucei.
abstract: SUMO, a reversible post-translational protein modifier, plays important roles in many processes of higher eukaryotic cell life. Although SUMO has been identified in many eukaryotes, SUMO and SUMO system are still unknown in some eukaryotic unicellular organisms, such as Trypanosoma brucei (T. brucei). In this study, only one SUMO homologue (TbSUMO) was identified in T. brucei. Expression of TbSUMO was knocked down by using RNA interference technique in procyclic-form T. brucei. The growth of TbSUMO-deficient cells was significantly inhibited. TbSUMO-deficient cells were arrested in G2/M phase accompanied with an obvious increase of 0N1K cells (zoids), and failed in chromosome segregation. These results indicate that TbSUMO is essential in cell cycle regulation, with one important role in mitosis. Meanwhile, the enrichment of zoids suggests the inhibition of mitosis does not prevent the cell division in procyclic-form T. brucei. HA-tagged TbSUMO was overexpressed in T. brucei and was shown to be localized to the nucleus through the whole cell cycle, further revealing its distinguished functions in nucleus. All these accumulated data imply that a SUMO system essential for regulating cell cycle progression might exist in the procyclic-form T. brucei.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
authors.forename: Shanhui
authors.initials: S
authors.lastname: Liao
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.forename: Kai
authors.initials: K
authors.lastname: Fan
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Tu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000963:Antimetabolites / Q000378:metabolism; D001973:Bromodeoxyuridine / Q000378:metabolism; D002453:Cell Cycle / Q000502:physiology*; D002467:Cell Nucleus / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D025842:SUMO-1 Protein / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D008941:Spindle Apparatus / Q000378:metabolism / Q000648:ultrastructure; D014346:Trypanosoma brucei brucei / Q000166:cytology / Q000502:physiology*
chemical_list: D000963:Antimetabolites; D015800:Protozoan Proteins; D025842:SUMO-1 Protein; D001973:Bromodeoxyuridine