Abstract:
:Box C/D snoRNPs, factors essential for ribosome biogenesis, are proposed to be assembled in the nucleoplasm before localizing to the nucleolus. However, recent work demonstrated the involvement of nuclear export factors in this process, suggesting that export may take place. Here we show that there are distinct distributions of U8 pre-snoRNAs and pre-snoRNP complexes in HeLa cell nuclear and cytoplasmic extracts. We observed differential association of nuclear export (PHAX, CRM1, and Ran) factors with complexes in the two extracts, consistent with nucleocytoplasmic transport. Furthermore, we show that the U8 pre-snoRNA in one of the cytoplasmic complexes contains an m3G cap and is associated with the nuclear import factor Snurportin1. Using RNA interference, we show that loss of either PHAX or Snurportin1 results in the incorrect localization of the U8 snoRNA. Our data therefore show that nuclear export and import factors are directly involved in U8 box C/D snoRNP biogenesis. The distinct distribution of U8 pre-snoRNP complexes between the two cellular compartments together with the association of both nuclear import and export factors with the precursor complex suggests that the mammalian U8 snoRNP is exported during biogenesis.
journal_name
Mol Cell Bioljournal_title
Molecular and cellular biologyauthors
Watkins NJ,Lemm I,Lührmann Rdoi
10.1128/MCB.00516-07subject
Has Abstractpub_date
2007-10-01 00:00:00pages
7018-27issue
20eissn
0270-7306issn
1098-5549pii
MCB.00516-07journal_volume
27pub_type
杂志文章abstract::Abundant approximately 28-nucleotide RNAs that are thought to direct histone H3 lysine 9 (H3K9) methylation and promote the elimination of nearly 15 Mbp of DNA from the developing somatic genome are generated during Tetrahymena thermophila conjugation. To identify the protein(s) that generates these small RNAs, we stu...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.25.20.9151-9164.2005
更新日期:2005-10-01 00:00:00
abstract::In Saccharomyces cerevisiae, COX5a and COX5b encode two distinct forms of cytochrome c oxidase subunit V, Va and Vb, respectively. To determine the relative contribution of COX5a and COX5b to cytochrome c oxidase function, we have disrupted each gene. Cytochrome c oxidase activity levels and respiration rates of strai...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.7.10.3520
更新日期:1987-10-01 00:00:00
abstract::We have developed an in vitro system which faithfully reproduces several aspects of general mRNA stability. Poly(A)- RNAs were rapidly and efficiently degraded in this system with no detectable intermediates by a highly processive 3'-to-5' exonuclease activity. The addition of a poly(A) tail of at least 30 bases, or a...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.17.1.398
更新日期:1997-01-01 00:00:00
abstract::Protein sumoylation plays an important but poorly understood role in controlling genome integrity. In Saccharomyces cerevisiae, the Slx5-Slx8 SUMO-targeted Ub ligase appears to be needed to ubiquitinate sumoylated proteins that arise in the absence of the Sgs1 DNA helicase. WSS1, a high-copy-number suppressor of a mut...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.01649-09
更新日期:2010-08-01 00:00:00
abstract::The mouse myosin light-chain 1A (MLC1A) gene, expressed in the atria of the adult heart, is one of the first muscle genes to be activated when skeletal as well as cardiac muscles form in the embryo. It is also transcribed in skeletal muscle cell lines at the onset of differentiation. Transient transfection assays of m...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.15.8.4585
更新日期:1995-08-01 00:00:00
abstract::A potential p120 GTPase-activating protein (RasGAP) effector, G3BP (RasGAP Src homology 3 [SH3] binding protein), was previously identified based on its ability to bind the SH3 domain of RasGAP. Here we show that G3BP colocalizes and physically interacts with RasGAP at the plasma membrane of serum-stimulated but not q...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.18.7.3956
更新日期:1998-07-01 00:00:00
abstract::Repeat-induced point mutation (RIP) is a process that efficiently detects DNA duplications prior to meiosis in Neurospora crassa and peppers them with G:C to A:T mutations. Cytosine methylation is typically associated with sequences affected by RIP, and methylated cytosines are not limited to CpG dinucleotides. We gen...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.15.10.5586
更新日期:1995-10-01 00:00:00
abstract::A mutant has been isolated from the J558 (immunoglobulin A, lambda, anti-alpha 1 leads to 3 dextran) cell line which synthesizes a heavy-chain immunoglobulin twice the size of normal heavy chain. Secondary variants that synthesized heavy chains either 1.5 times as large as wild type or the same size as wild type were ...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.2.9.1134
更新日期:1982-09-01 00:00:00
abstract::The six human telomeric proteins TRF1, TRF2, RAP1, TIN2, POT1, and TPP1 can form a complex called the telosome/shelterin, which is required for telomere protection and length control. TPP1 has been shown to regulate both POT1 telomere localization and telosome assembly through its binding to TIN2. It remains to be det...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.00603-07
更新日期:2007-08-01 00:00:00
abstract::Over 400 Krüppel-associated box zinc finger proteins (KRAB-ZFPs) are encoded in mammalian genomes. While KRAB-ZFPs strongly repress transcription in vitro, little is known about their biological function or gene targets in vivo. Regulator of sex limitation 1 (Rsl1), one of the first KRAB-Zfp genes assigned a physiolog...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.00615-12
更新日期:2012-09-01 00:00:00
abstract::Mutant strain d48 of Paramecium tetraurelia lacks the gene for antigen A in the macronucleus, whereas this gene is present in the micronucleus. Transfer of macronucleoplasm from the wild type to strain d48 caused d48 to revert to the wild type after autogamy. Transfer of cytoplasm was not as effective as transfer of m...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.6.10.3498
更新日期:1986-10-01 00:00:00
abstract::The tumor suppressor p21 acts as a cell cycle inhibitor and has also been shown to regulate gene expression by functioning as a transcription corepressor. Here, we identified p21-regulated microRNAs (miRNAs) by sequencing small RNAs from isogenic p21(+/+) and p21(-/-) cells. Three abundant miRNA clusters, miR-200b-200...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.01043-13
更新日期:2014-02-01 00:00:00
abstract::The CD28 costimulatory signal enhances antigen-mediated induction of interleukin-2 (IL-2) gene transcription through activation of an enhancer termed the CD28-responsive element (CD28RE). Although various nuclear proteins have been shown to bind to CD28RE, their in vivo functions in the regulation of this enhancer rem...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.17.5.2605
更新日期:1997-05-01 00:00:00
abstract::The ligand-binding domains of thyroid hormone (L-triiodothyronine [T3]) receptors (T3Rs), all-trans retinoic acid (RA) receptors (RARs), and 9-cis RA receptors (RARs and RXRs) contain a series of heptad motifs thought to be important for dimeric interactions. Using a chimera containing amino acids 120 to 392 of chicke...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.14.9.5756
更新日期:1994-09-01 00:00:00
abstract::Expression of the granulocyte-macrophage colony-stimulating factor (GM-CSF) gene in T cells is activated by the combination of phorbol ester (phorbol myristate acetate) and calcium ionophore (A23187), which mimic antigen stimulation through the T-cell receptor. We have previously shown that a fragment containing bp -9...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.13.12.7399
更新日期:1993-12-01 00:00:00
abstract::We investigated the interaction of phospholipase C-gamma (PLC-gamma) with wild-type and mutant forms of the platelet-derived growth factor (PDGF) beta-receptor both in vivo and in vitro. After PDGF treatment of CHO cell lines expressing wild-type or either of two mutant (delta Ki and Y825F) PDGF receptors, PLC-gamma b...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.10.5.2359
更新日期:1990-05-01 00:00:00
abstract::During spermatogenesis, several genes are expressed in a germ cell-specific manner. Previous studies have demonstrated that rat and mouse spermatogenic cells produce a 1,700-nucleotide proenkephalin RNA, while somatic cells that express the proenkephalin gene contain a 1,450-nucleotide transcript. Using cDNA cloning, ...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.10.7.3717
更新日期:1990-07-01 00:00:00
abstract::Welander distal myopathy (WDM) is a muscle dystrophy characterized by adult-onset distal muscle weakness, prevalently impacting the distal long extensors of the hands and feet. WDM is an autosomal dominant disorder caused by a missense mutation (c.1362G>A; p.E384K) in the TIA1 (T-cell intracellular antigen 1) gene, wh...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.00299-18
更新日期:2018-12-11 00:00:00
abstract::Changes in chromatin composition are often a prerequisite for gene induction. Nonallelic histone variants have recently emerged as key players in transcriptional control and chromatin modulation. While the changes in chromatin accessibility and histone posttranslational modification (PTM) distribution that accompany g...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.01590-08
更新日期:2009-04-01 00:00:00
abstract::Murine embryonic stem (ES) cells are defined by continuous self-renewal and pluripotency. A diverse repertoire of protein isoforms arising from alternative splicing is expressed in ES cells without defined biological roles. Sall4, a transcription factor essential for pluripotency, exists as two isoforms (Sall4a and Sa...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.00419-10
更新日期:2010-11-01 00:00:00
abstract::Transcriptional insulators are cis regulatory elements that organize chromatin into independently regulated domains. At the imprinted murine Igf2/H19 locus, the H19-ICR insulator prevents the activation of the Igf2 promoter on the maternal allele by enhancers that activate H19 on the same chromosome. Given the well-de...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.00091-08
更新日期:2008-06-01 00:00:00
abstract::The telomeric single-strand DNA binding protein protection of telomeres 1 (POT1) protects telomeres from rapid degradation in Schizosaccharomyces pombe and has been implicated in positive and negative telomere length regulation in humans. Human POT1 appears to interact with telomeres both through direct binding to the...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.25.2.808-818.2005
更新日期:2005-01-01 00:00:00
abstract::Mammalian cells were observed to die under conditions in which nutrients were depleted and, simultaneously, macroautophagy was inhibited either genetically (by a small interfering RNA targeting Atg5, Atg6/Beclin 1-1, Atg10, or Atg12) or pharmacologically (by 3-methyladenine, hydroxychloroquine, bafilomycin A1, or mone...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.25.3.1025-1040.2005
更新日期:2005-02-01 00:00:00
abstract::Cellular senescence is an irreversible growth arrest and is presumed to be a natural barrier to tumor development. Like telomere shortening, certain defects in chromosome integrity can trigger senescence; however, the roles of centromere proteins in regulating commitment to the senescent state remains to be establishe...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.01318-09
更新日期:2010-05-01 00:00:00
abstract::We have characterized features of the site recognized by a double-stranded DNA endonuclease, I-SceII, encoded by intron 4 alpha of the yeast mitochondrial COX1 gene. We determined the effects of 36 point mutations on the cleavage efficiency of natural and synthetic substrates containing the Saccharomyces capensis I-Sc...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.12.2.716
更新日期:1992-02-01 00:00:00
abstract::The growth suppressor activities of the RB and p107 products are believed to be mediated by the reversible binding of a heterogeneous family of cellular proteins to a conserved T/E1A pocket domain that is present within both proteins. To study the functional role of these interactions, we examined the properties of ce...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.14.11.7256
更新日期:1994-11-01 00:00:00
abstract::TRAIL is an endogenous death receptor ligand also used therapeutically because of its selective proapoptotic activity in cancer cells. In the present study, we examined chromatin alterations induced by TRAIL and show that TRAIL induces a rapid activation of DNA damage response (DDR) pathways with histone H2AX, Chk2, A...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.00581-08
更新日期:2009-01-01 00:00:00
abstract::The activation of p70s6k is associated with multiple phosphorylations at two sets of sites. The first set, S411, S418, T421, and S424, reside within the autoinhibitory domain, and each contains a hydrophobic residue at -2 and a proline at +1. The second set of sites, T229 (in the catalytic domain) and T389 and S404 (i...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.17.9.5648
更新日期:1997-09-01 00:00:00
abstract::Growth, patterning, and apoptosis are mutually interactive during development. For example, cells that select an abnormal fate in a developing field are frequently removed by apoptosis. An important issue in this process that needs to be resolved is the mechanism used by cells to discern their correct fate from an abn...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.25.8.3140-3150.2005
更新日期:2005-04-01 00:00:00
abstract::The lactogenic hormones, i.e., prolactin and glucocorticoids, act in concert to stimulate transcription factors responsible for hormone-dependent milk protein gene expression. In the mammary gland, prolactin activates Stat5a and Stat5b and glucocorticoids activate the glucocorticoid receptor (GR). Immunoprecipitation ...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.18.4.1783
更新日期:1998-04-01 00:00:00