The RCC1 protein, a regulator for the onset of chromosome condensation locates in the nucleus and binds to DNA

Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka, Japan.
The Journal of Cell Biology (Impact Factor: 9.83). 11/1989; 109(4 Pt 1):1389-97.
Source: PubMed


The RCC1 gene, a regulator for the onset of chromosome condensation was found to encode a protein with a molecular mass of 45 kD, determined using the antibody against the synthetic peptides prepared according to the amino acid sequence of the putative RCC1 protein. The p45 located in the nuclei was released from the isolated nuclei, either by DNase I digestion or by treatment with 0.3 M NaCl. Consistently, p45 bound to the DNA-cellulose column was eluted with 0.3 M NaCl. After sequential treatment with DNase I and 2 M NaCl, almost all of the RCC1 protein were released from the nuclei. Thus, RCC1 protein locates on the chromatin and is not a component of the nuclear matrix. In mitotic cells, p45 is dispersed into the cytoplasm. Presumably, RCC1 protein plays a role in regulating the onset of chromosome condensation, at the level of transcription or of mRNA maturation.

Full-text preview

Available from: PubMed Central
  • Source
    • "In this way, RanGAP1 activity is concentrated at the cytoplasmic side of the NPC. On the other hand, RanGEF/RCC1, which converts Ran-GDP to Ran-GTP, is a chromatin-associated protein and its activity is concentrated in the nucleus (Ohtsubo et al., 1987Ohtsubo et al., , 1989; Bischoff and Ponstingl, 1991a,b;Figure 1A). This biased localization of RanGAP1 and RanGEF/RCC1 generates the gradient of Ran-GTP between the nucleus and the cytoplasm. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Ran, a small GTPase, is required for the spindle formation and nuclear envelope (NE) formation. After NE breakdown (NEBD) during mitosis in metazoan cells, the Ran-GTP gradient across the NE is lost and Ran-GTP becomes concentrated around chromatin, thus affecting the stability of microtubules and promoting the assembly of spindle microtubules and segregation of chromosomes. Mitosis in which chromosomes are segregated subsequent to NEBD is called “open mitosis.” In contrast, many fungi undergo a process termed “closed mitosis” in which chromosome segregation and spindle formation occur without NEBD. Although the fission yeast Schizosaccharomyces pombe undergoes a closed mitosis, it exhibits a short period during meiosis (anaphase of the second meiosis; called “anaphase II”) when nuclear and cytoplasmic proteins are mixed in the presence of intact NE and nuclear pore complexes (NPC). This “virtual” nuclear envelope breakdown (vNEBD) involves changes in the localization of RanGAP1, an activator of Ran-GTP hydrolysis. Recently, Nup132, a component of the structural core Nup107-160 subcomplex of the NPC, has been shown to be involved in the maintenance of the nuclear cytoplasmic barrier in yeast meiosis. In this review, we highlight the possible roles of RanGAP1 and Nup132 in vNEBD and discuss the biological significance of vNEBD in S. pombe meiosis.
    Preview · Article · Feb 2016 · Frontiers in Cell and Developmental Biology
  • Source
    • "Both systems utilize open mitosis, where the nuclear envelope breaks down fully and cytoplasmic and nuclear contents— including Ran—mingle during mitosis (Hutchins et al., 2009). RCC1 binds to chromatin (Ohtsubo et al., 1989; England et al., 2010), and through its interaction with Histones (Nemergut et al., 2001; Makde et al., 2010) and DNA (Chen et al., 2007), generates a locally high concentration of Ran.GTP (Bischoff and Ponstingl, 1991). As Ran.GTP diffuses away from the chromatin, RanGAP induces GTP hydrolysis, and Ran.GTP is converted to Ran.GDP (Kalab and Heald, 2008); an activity enhanced by RanBP1 (Seewald et al., 2003). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Over the last two decades, the small GTPase Ran has emerged as a central regulator of both mitosis and meiosis, particularly in the generation, maintenance, and regulation of the microtubule (MT)-based bipolar spindle. Ran-regulated pathways in mitosis bear many similarities to the well-characterized functions of Ran in nuclear transport and, as with transport, the majority of these mitotic effects are mediated through affecting the physical interaction between karyopherins and Spindle Assembly Factors (SAFs)—a loose term describing proteins or protein complexes involved in spindle assembly through promoting nucleation, stabilization, and/or depolymerization of MTs, through anchoring MTs to specific structures such as centrosomes, chromatin or kinetochores, or through sliding MTs along each other to generate the force required to achieve bipolarity. As such, the Ran-mediated pathway represents a crucial functional module within the wider spindle assembly landscape. Research into mitosis using the model organism Drosophila melanogaster has contributed substantially to our understanding of centrosome and spindle function. However, in comparison to mammalian systems, very little is known about the contribution of Ran-mediated pathways in Drosophila mitosis. This article sets out to summarize our understanding of the roles of the Ran pathway components in Drosophila mitosis, focusing on the syncytial blastoderm embryo, arguing that it can provide important insights into the conserved functions on Ran during spindle formation.
    Full-text · Article · Nov 2015 · Frontiers in Cell and Developmental Biology
  • Source
    • "NTRs are generally recruited to their cargos by forming interactions with specific nuclear export signals (NES) or nuclear localization signals (NLS) that can be short peptide sequences, nucleotide motifs or structural features of their substrates. The directionality of transport is determined by the asymmetric distribution of the GTP-bound state of the Ras-like GTPase Ran across the nuclear membrane, which is maintained in its GTP-bound state in the nucleus by the chromatinassociated Ran guanine nucleotide exchange factor (RanGEF; RCC1 in humans and Prp20 in yeast [14] [15]). Conversely, the Ran GTPase activating protein (RanGAP; RanGAP1 in humans and Rna1 in yeast) is localized on the cytoplasmic side of the nuclear envelope and stimulates hydrolysis of GTP bound to Ran, resulting in low levels of cytoplasmic RanGTP [16] [17]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: RNAs and ribonucleoprotein complexes (RNPs) play key roles in mediating and regulating gene expression. In eukaryotes, most RNAs are transcribed, processed and assembled with proteins in the nucleus and then either function in the cytoplasm or also undergo a cytoplasmic phase in their biogenesis. This compartmentalisation ensures that sequential steps in gene expression and RNP production are performed in the correct order and allows important quality control mechanisms that prevent the involvement of aberrant RNAs/RNPs in these cellular pathways. The selective exchange of RNAs/RNPs between the nucleus and cytoplasm is enabled by nuclear pore complexes (NPCs), which function as gateways between these compartments. RNA/RNP transport is facilitated by a range of nuclear transport receptors and adaptors, which are specifically recruited to their cargos and mediate interactions with nucleoporins to allow directional translocation through NPCs. While some transport factors are only responsible for the export/import of a certain class of RNA/RNP, others are multifunctional and, in the case of large RNPs, several export factors appear to work together to bring about export. Recent structural studies have revealed aspects of the mechanisms employed by transport receptors to enable specific cargo recognition, and genome-wide approaches have provided the first insights into the diverse composition of pre-mRNPs during export. Furthermore, the regulation of RNA/RNP export is emerging as an important means to modulate gene expression in stress conditions and disease.
    Full-text · Article · Oct 2015 · Journal of Molecular Biology
Show more