Expression and Functional Dynamics of the XCAP-D2 Condensin Subunit in Xenopus laevis Oocytes

• Published in: The Journal of biological chemistry Vol. 278; no. 28; pp. 25708 - 25715
• Main Authors: Watrin, Erwan, Cubizolles, Fabien, Osborne, H.Beverley, Le Guellec, Katherine, Legagneux, Vincent
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 11.07.2003; American Society for Biochemistry and Molecular Biology
• Subjects: 5' Untranslated Regions; Adenosine Triphosphatases; Adenosine Triphosphatases - biosynthesis; Adenosine Triphosphatases - chemistry; Adenosine Triphosphatases - physiology; Animals; Base Sequence; Blotting, Western; CAP-D2 protein; Carrier Proteins; Carrier Proteins - chemistry; Centrifugation, Density Gradient; Chromatin; Chromatin - metabolism; condensin; Development Biology; Dimerization; DNA-Binding Proteins; DNA-Binding Proteins - biosynthesis; DNA-Binding Proteins - chemistry; DNA-Binding Proteins - physiology; Female; Freshwater; Life Sciences; Male; Meiosis; Metaphase; Mitosis; Molecular Sequence Data; Multiprotein Complexes; Oligonucleotides, Antisense; Oligonucleotides, Antisense - pharmacology; Oocytes; Oocytes - metabolism; Precipitin Tests; Progesterone; Progesterone - metabolism; RNA, Messenger; RNA, Messenger - metabolism; Spermatozoa; Spermatozoa - metabolism; Sucrose; Sucrose - pharmacology; Time Factors; Xenopus; Xenopus laevis
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M300192200

The 13 S condensin complex plays a crucial role in the condensation and segregation of the two sets of chromosomes during mitosis in vivo as well as in cell-free extracts. This complex, conserved from yeast to human, contains a heterodimer of structural maintenance of chromosome (SMC) family proteins and three additional non-SMC subunits. We have investigated the expression of the non-SMC condensin component XCAP-D2 in Xenopus laevis oocytes. When studied during meiotic maturation, XCAP-D2 starts to accumulate at the time of germinal vesicle breakdown and reaches its maximal amount in metaphase II oocytes. This accumulation is specifically blocked by injection of antisense oligonucleotides. XCAP-D2 antisense-injected oocytes progress normally through meiosis until metaphase II. At this stage, however, chromosomes exhibit architecture defaults, and resolution of sister chromatids is impaired. Surprisingly, in mitotic extracts made from XCAP-D2 knocked-down oocytes, sperm chromatin normally condenses into compacted chromosomes, whereas the amounts of both free and chromosome-bound XCAP-D2 are markedly reduced. This apparent discrepancy is discussed in light of current knowledge on chromosome dynamics.