XB-S is a protein with an amino-terminal-truncated form of tenascin-X (TNXB). However, the precise roles of XB-S in vivo are unknown. In this study, to determine the role of XB-S in vivo, we screened XB-S-binding proteins. FLAG-tagged XB-S was transiently introduced into 293T cells. Then its associated proteins were purified by immunoprecipitation using an anti-FLAG antibody and its components were identified by mass spectrometric analyses. Mitotic motor kinesin Eg5 was identified in the immunoprecipitates. XB-S and Eg5 proteins were co-localized in the cytoplasm in interphase and mitosis, but XB-S did not localize on mitotic spindle microtubules, on which Eg5 prominently localized in mitosis. As for Eg5 binding to XB-S, glutathione S-transferase-fused XB-S expressed in vitro directly bound to full-length Eg5 translated in reticulocyte lysate, and the XB-S-binding region was located in the motor domain of Eg5. Furthermore, during cell cycle progression XB-S showed a similar expression profile to that of Eg5. These results suggest possible involvement of XB-S in the function of Eg5.
Mitosis Spindle Tenascin-X TNXA TNXB XB-S
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We thank Kiyomi Takaya for her technical assistance. This work was supported in part by Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan.
Shen L, Wu LC, Sanlioglu S et al (1994) Structure and genetics of the partially duplicated gene RP located immediately upstream of the complement C4A and the C4B genes in the HLA class III region. J Biol Chem 269:8466–8476PubMedGoogle Scholar
Blanchong CA, Zhou B, Rupert KL et al (2000) Deficiencies of human complement component C4A and C4B and heterozygosity in length variants of RP-C4-CYP21-TNX (RCCX) modules in caucasians The load of RCCX genetic diversity on major histocompatibility complex-associated disease. J Exp Med 191:2183–2196. doi:10.1084/jem.191.12.2183CrossRefPubMedGoogle Scholar
Kamatani Y, Matsuda K, Ohishi T et al (2008) Identification of a significant association of a single nucleotide polymorphism in TNXB with systemic lupus erythematosus in a Japanese population. J Hum Genet 53:64–73. doi:10.1007/s10038-007-0219-1CrossRefPubMedGoogle Scholar
Gitelman SE, Bristow J, Miller WL (1992) Mechanism and consequences of the duplication of the human C4/P450c21/gene X locus. Mol Cell Biol 12:2124–2134PubMedGoogle Scholar
Tee MK, Thomson AA, Bristow J et al (1995) Sequences promoting the transcription of the human XA gene overlapping P450c21A correctly predict the presence of a novel, adrenal-specific, truncated form of tenascin-X. Genomics 28:171–178. doi:10.1006/geno.1995.1128CrossRefPubMedGoogle Scholar
Matsumoto K, Arai M, Ishihara N et al (1992) Cluster of fibronectin type III repeats found in the human major histocompatibility complex class III region shows the highest homology with the repeats in an extracellular matrix protein, tenascin. Genomics 12:485–491. doi:10.1016/0888-7543(92)90438-XCrossRefPubMedGoogle Scholar
Satou A, Taira T, Iguchi-Ariga SM et al (2001) A novel transrepression pathway of c-Myc. Recruitment of a transcriptional corepressor complex to c-Myc by MM-1, a c-Myc-binding protein. J Biol Chem 276:46562–46567. doi:10.1074/jbc.M104937200CrossRefPubMedGoogle Scholar
Le Guellec R, Paris J, Couturier A et al (1991) Cloning by differential screening of a Xenopus cDNA that encodes a kinesin-related protein. Mol Cell Biol 11:3395–3398PubMedGoogle Scholar
Uzbekov R, Prigent C, Arlot-Bonnemains Y (1999) Cell cycle analysis and synchronization of the Xenopus laevis XL2 cell line: study of the kinesin related protein XlEg5. Microsc Res Tech 45:31–42. doi :10.1002/(SICI)1097-0029(19990401)45:1<31::AID-JEMT3>3.0.CO;2-KCrossRefPubMedGoogle Scholar
Németh AL, Medveczky P, Tóth J et al (2007) Unconventional translation initiation of human trypsinogen 4 at a CUG codon with an N-terminal leucine. A possible means to regulate gene expression. FEBS J 274:1610–1620. doi:10.1111/j.1742-4658.2007.05708.xGoogle Scholar
Yu PJ, Ferrari G, Galloway AC, et al (2007) Basic fibroblast growth factor (FGF-2): the high molecular weight forms come of age. J Cell Biochem 100(5):1100–1108. doi:10.1002/jcb.21116Google Scholar