Heterochromatin protein 1, a known suppressor of position-effect variegation, is highly conserved in<i>Drosophila</i>

Clark, Robert F.; Elgin, Sarah C. R.

doi:10.1093/nar/20.22.6067

Cited by 34 publications

(28 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…HP1, a constitutive heterochromatin component, has been well documented for its function in heterochromatin formation (Clark and Elgin, 1992;Kourmouli et al, 2004;Schotta et al, 2004). Increased HP1 levels through the Hsp70-HP1 transgene led to increased variegations ( Fig.…”

Section: Drosophila Caf-1 P180 Suppresses Pevs That Affect Euchromatimentioning

confidence: 95%

DrosophilaCAF-1 regulates HP1-mediated epigenetic silencing and pericentric heterochromatin stability

Huang

Zhang

et al. 2010

Journal of Cell Science

View full text Add to dashboard Cite

SummaryChromatin assembly factor 1 (CAF-1) was initially characterized as a histone deliverer in the process of DNA-replication-coupled chromatin assembly in eukaryotic cells. Here, we report that CAF-1 p180, the largest subunit of Drosophila CAF-1, participates in the process of heterochromatin formation and functions to maintain pericentric heterochromatin stability. We provide evidence that Drosophila CAF-1 p180 plays a role in both classes of position effect variegation (PEV) and in the expression of heterochromatic genes. A decrease in the expression of Drosophila CAF-1 p180 leads to a decrease in both H3K9 methylation at pericentric heterochromatin regions and the recruitment of heterochromatin protein 1 (HP1) to the chromocenter of the polytene chromosomes. The artificial targeting of HP1 to a euchromatin location leads to the enrichment of Drosophila CAF-1 p180 at this ectopic heterochromatin, suggesting the mutual recruitment of HP1 and CAF-1 p180. We also show that the spreading of heterochromatin is compromised in flies that have reduced CAF-1 p180. Furthermore, reduced CAF-1 p180 causes a defect in the dynamics of heterochromatic markers in early Drosophila embryos. Together, these findings suggest that Drosophila CAF-1 p180 is an essential factor in the epigenetic control of heterochromatin formation and/or maintenance.

show abstract

Section: Drosophila Caf-1 P180 Suppresses Pevs That Affect Euchromatimentioning

confidence: 95%

DrosophilaCAF-1 regulates HP1-mediated epigenetic silencing and pericentric heterochromatin stability

Huang

Zhang

et al. 2010

Journal of Cell Science

View full text Add to dashboard Cite

show abstract

“…W293 is almost invariant among HP1 proteins (in D. melanogaster and D. virilis HP1 proteins the equivalent position is occupied a conservative F residue [8]). A W293-G substitution resulted in loss of complementation ( Table 1) and confirms that an intact CSD is necessary for swi6p activity.…”

Section: Functional Domains Of the Swi6p Proteinmentioning

confidence: 99%

Conservation of Heterochromatin Protein 1 Function

Wang

Chow

et al. 2000

Molecular and Cellular Biology

124

121

View full text Add to dashboard Cite

Heterochromatin represents a cytologically visible state of heritable gene repression. In the yeast, Schizosaccharomyces pombe, the swi6 gene encodes a heterochromatin protein 1 (HP1)-like chromodomain protein that localizes to heterochromatin domains, including the centromeres, telomeres, and the donor mating-type loci, and is involved in silencing at these loci. We identify here the functional domains of swi6p and demonstrate that the chromodomain from a mammalian HP1-like protein, M31, can functionally replace that of swi6p, showing that chromodomain function is conserved from yeasts to humans. Site-directed mutagenesis, based on a modeled three-dimensional structure of the swi6p chromodomain, shows that the hydrophobic amino acids which lie in the core of the structure are critical for biological function. Gel filtration, gel overlay experiments, and mass spectroscopy show that HP1 proteins can self-associate, and we suggest that it is as oligomers that HP1 proteins are incorporated into heterochromatin complexes that silence gene activity.The highly conserved heterochromatin protein 1 (HP1) class of chromobox genes (HP1) encode structural adapters whose probable role is to assemble a variety of macromolecular complexes in chromatin (30). The possible functions of these complexes are wide-ranging and include roles in transcriptional repression (12,36,54,55), transgene silencing (17, 26), chromosome segregation (14, 31), recruitment of silent genes to heterochromatin (7, 54), localization of heterochromatin to the nuclear periphery (67), and sex chromosome inactivation during mammalian spermatogenesis (44).The swi6 gene in Schizosaccharomyces pombe is a nonessential gene that is required for the recombination-suppression and silencing which encompasses the mat2-K-mat3 region (33). Cloning of the gene showed that swi6 is a member of the HP1 class of chromobox genes (38), suggesting that the recombination-suppression and silencing are due to the packaging of the mat2-K-mat3 region into a heterochromatin-like complex that renders the region inaccessible to the transcriptional and recombination machinery (38,63). Other trans-acting factors that are required for repression at the silent loci include rik1, clr1, clr2, clr3, clr4, and clr6 (34, 64). rik1, clr1, and clr4 are thought to encode structural components of the heterochromatin-like complex, while clr3 and clr6 share considerable homology with histone deacetylases (20). Along with the silent mating-type loci, swi6p is also involved in silencing at the fission yeast centromeres and telomeres (14, 47) and plays a role in chromosome segregation at anaphase (14).HP1 proteins are characterized by the possession of both a classical chromodomain (CD) and a chromo shadow domain (CSD) (2) linked by a variable intervening region (IVR) or "hinge" (16). In addition, a stretch of acidic amino acids immediately precedes the CD of HP1 proteins (see Fig. 1A). The solution structure of the CD from the murine HP1-like heterochromatin-associated protein, M31 (also known as mH...

show abstract

“…The cDNA sequences of HP1 homolog contain wellconserved N-terminal and C-terminal domains (Clark and Elgin 1992). Within the open reading frame of the isolated clone (Fig.…”

Section: Cdna Sequence and Protein Characterizationmentioning

confidence: 99%

Heterochromatin protein HP1 Hsβ (p25β) and its localization with centromeres in mitosis

et al. 1997

View full text Add to dashboard Cite

Some autoimmune sera containing anticentromere autoantibodies also recognize a doublet of Mr 23 000 (p23) and 25 000 (p25) in addition to CENP (centromere protein)-A (Mr 19 000), -B (Mr 80 000), and -C (Mr 140 000). A p25 antigen (HP1(Hsalpha)) has been shown to be a human homolog of Drosophila HP1 (heterochromatin protein 1). We have isolated a cDNA clone encoding another form of p25 (HP1(Hsbeta ) or p25beta) from a lambdaZap HepG2 library using human autoimmune serum. The deduced amino acid sequence of the clone contained a conserved chromodomain (chromatin modifier domain) in the N-terminal region and a heterochromatin binding domain in the C-terminal region. In immunofluorescence experiments, only affinity purified antibodies reactive with the C-terminal (amino acids 70-185) domain showed nucleoplasmic and heterochromatin staining, whereas N-terminal (amino acids 1-115) specific antibodies were nonreactive. In metaphase chromosome spreads, the C-terminal domain antibody was also localized to the centromeric regions of chromosomes. Association with centromeres was most prominent at anaphase and changed to a more generalized association with whole chromosomes in telophase. The cooccurrence of autoantibodies to centromere proteins and HP1 in certain autoimmune diseases might be a reflection of coordinated immune responses to these closely associated sets of proteins.

show abstract

Heterochromatin protein 1, a known suppressor of position-effect variegation, is highly conserved inDrosophila

Cited by 34 publications

References 45 publications

DrosophilaCAF-1 regulates HP1-mediated epigenetic silencing and pericentric heterochromatin stability

DrosophilaCAF-1 regulates HP1-mediated epigenetic silencing and pericentric heterochromatin stability

Conservation of Heterochromatin Protein 1 Function

Heterochromatin protein HP1 Hsβ (p25β) and its localization with centromeres in mitosis

Contact Info

Product

Resources

About