scholarly journals Chromatin structure of the HLA-DR alpha gene in different functional states of major histocompatibility complex class II gene expression.

1987 ◽  
Vol 7 (5) ◽  
pp. 1967-1972 ◽  
Author(s):  
B M Peterlin ◽  
K J Hardy ◽  
A S Larsen
Keyword(s):  
Dna Sequences ◽  
Chromatin Structure ◽  
Gene Promoter ◽  
Dnase I ◽  
Consensus Sequences ◽  
Histocompatibility Complex ◽  
Hla Dr ◽  
Hypersensitive Sites ◽  
Alpha Gene ◽  
Regulatory Loci

We utilized DNase I hypersensitivity mapping to study chromatin structure within the HLA-DR alpha gene. We found a single DNase I-hypersensitive site coinciding with the HLA-DR alpha gene promoter in all cells studied. Moreover, in cells that constitutively express HLA-DR, two additional DNase I-hypersensitive sites were observed. These lie within the first intron of the HLA-DR alpha gene and encompass DNA sequences that share homologies with regulatory loci of the immunoglobulin and immune response genes, as well as with core enhancer consensus sequences.

Chromatin structure of the HLA-DR alpha gene in different functional states of major histocompatibility complex class II gene expression

1987 ◽  
Vol 7 (5) ◽  
pp. 1967-1972
Author(s):  
B M Peterlin ◽  
K J Hardy ◽  
A S Larsen
Keyword(s):  
Dna Sequences ◽  
Chromatin Structure ◽  
Gene Promoter ◽  
Dnase I ◽  
Consensus Sequences ◽  
Histocompatibility Complex ◽  
Hla Dr ◽  
Hypersensitive Sites ◽  
Alpha Gene ◽  
Regulatory Loci

We utilized DNase I hypersensitivity mapping to study chromatin structure within the HLA-DR alpha gene. We found a single DNase I-hypersensitive site coinciding with the HLA-DR alpha gene promoter in all cells studied. Moreover, in cells that constitutively express HLA-DR, two additional DNase I-hypersensitive sites were observed. These lie within the first intron of the HLA-DR alpha gene and encompass DNA sequences that share homologies with regulatory loci of the immunoglobulin and immune response genes, as well as with core enhancer consensus sequences.

scholarly journals A tissue-specific transcriptional enhancer is found in the body of the HLA-DR alpha gene.

1987 ◽  
Vol 166 (3) ◽  
pp. 625-636 ◽  
Author(s):  
Y Wang ◽  
A S Larsen ◽  
B M Peterlin
Keyword(s):  
Dna Sequences ◽  
Regulatory Elements ◽  
Chloramphenicol Acetyltransferase ◽  
The Body ◽  
Transcriptional Enhancer ◽  
Tissue Specific ◽  
Cis Acting ◽  
Hla Dr ◽  
Hypersensitive Sites ◽  
Alpha Gene

We mapped cis-acting regulatory elements in the HLA-DR alpha gene, which encodes the monomorphic subunit of the HLA-DR heterodimer. Genomic fragments of HLA-DR alpha were placed 5' or 3' to the chloramphenicol acetyltransferase reporter gene, the transcription of which was initiated from the Herpes simplex thymidine kinase promoter. In transient expression assays, fragments from the body of the HLA-DR alpha gene were able to increase chloramphenicol acetyltransferase activity in a position-, orientation-, and promoter-independent yet tissue-specific fashion. These HLA-DR alpha cis-acting regulatory elements contain previously identified DNase I-hypersensitive sites and DNA sequences homologous to those found in other eukaryotic transcriptional enhancers.

scholarly journals Inherited immunodeficiency with a defect in a major histocompatibility complex class II promoter-binding protein differs in the chromatin structure of the HLA-DRA gene

1989 ◽  
Vol 9 (1) ◽  
pp. 296-302
Author(s):  
P Gönczy ◽  
W Reith ◽  
E Barras ◽  
B Lisowska-Grospierre ◽  
C Griscelli ◽  
...  
Keyword(s):  
Major Histocompatibility Complex ◽  
Major Histocompatibility Complex Class ◽  
Chromatin Structure ◽  
Class Ii ◽  
Dnase I ◽  
Complex Class ◽  
Dnase I Hypersensitive Sites ◽  
Histocompatibility Complex ◽  
Hypersensitive Sites ◽  
Fibroblastic Cells

A defect in a trans-regulatory factor which controls major histocompatibility complex class II gene expression is responsible for an inherited form of immunodeficiency with a lack of expression of human leukocyte antigen (HLA) class II antigens. We have recently described and cloned an HLA class II promoter DNA-binding protein, RF-X, present in normal B cells and absent in these class II-deficient regulatory mutants. Here we report that these in vitro results correlate with a specific change in the chromatin structure of the class II promoter: two prominent DNase I-hypersensitive sites were identified in the promoter of the HLA-DRA gene in normal B lymphocytes and found to be absent in the class II-deficient mutant cells. The same two prominent DNase I-hypersensitive sites were observed in normal fibroblastic cells induced by gamma interferon to express class II genes. Interestingly, they were also observed in the uninduced class II-negative fibroblastic cells, which have also been shown to have a normal RF-X binding pattern. We conclude that the two DNase I-hypersensitive sites in the HLA-DRA promoter reflect features in chromatin structure which correlate with the binding of the trans-acting factor RF-X and which are necessary but not sufficient for the expression of class II genes.

scholarly journals Inherited immunodeficiency with a defect in a major histocompatibility complex class II promoter-binding protein differs in the chromatin structure of the HLA-DRA gene.

1989 ◽  
Vol 9 (1) ◽  
pp. 296-302 ◽  
Author(s):  
P Gönczy ◽  
W Reith ◽  
E Barras ◽  
B Lisowska-Grospierre ◽  
C Griscelli ◽  
...  
Keyword(s):  
Major Histocompatibility Complex ◽  
Major Histocompatibility Complex Class ◽  
Chromatin Structure ◽  
Class Ii ◽  
Dnase I ◽  
Complex Class ◽  
Dnase I Hypersensitive Sites ◽  
Histocompatibility Complex ◽  
Hypersensitive Sites ◽  
Fibroblastic Cells

A defect in a trans-regulatory factor which controls major histocompatibility complex class II gene expression is responsible for an inherited form of immunodeficiency with a lack of expression of human leukocyte antigen (HLA) class II antigens. We have recently described and cloned an HLA class II promoter DNA-binding protein, RF-X, present in normal B cells and absent in these class II-deficient regulatory mutants. Here we report that these in vitro results correlate with a specific change in the chromatin structure of the class II promoter: two prominent DNase I-hypersensitive sites were identified in the promoter of the HLA-DRA gene in normal B lymphocytes and found to be absent in the class II-deficient mutant cells. The same two prominent DNase I-hypersensitive sites were observed in normal fibroblastic cells induced by gamma interferon to express class II genes. Interestingly, they were also observed in the uninduced class II-negative fibroblastic cells, which have also been shown to have a normal RF-X binding pattern. We conclude that the two DNase I-hypersensitive sites in the HLA-DRA promoter reflect features in chromatin structure which correlate with the binding of the trans-acting factor RF-X and which are necessary but not sufficient for the expression of class II genes.

Major histocompatibility complex class I genes in murine fibrosarcoma IC9 are down regulated at the level of the chromatin structure

1989 ◽  
Vol 9 (7) ◽  
pp. 3136-3142
Author(s):  
U Maschek ◽  
W Pülm ◽  
S Segal ◽  
G J Hämmerling
Keyword(s):  
Major Histocompatibility Complex ◽  
Major Histocompatibility Complex Class ◽  
Chromatin Structure ◽  
Dnase I ◽  
Class I ◽  
Micrococcal Nuclease ◽  
Complex Class ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Nuclear Extracts

The fibrosarcoma IC9 is deficient in the expression of the major histocompatibility complex class I genes Kb, Kk, and Dk and expresses only the Db molecule. Because class I deficiency may enable tumor cells to escape the immune response by cytotoxic T lymphocytes, we investigated why the class I genes are not expressed. Expression of the silent class I genes could not be induced, but all known DNA-binding factors specific for class I genes could be detected in nuclear extracts of IC9 cells. After cloning of the silent Kb gene from the IC9 cells and subsequent transfection of this cloned Kb gene into LTK- and IC9 cells, normal Kb antigens were expressed on the cell surface of both cell lines. Digestion of the chromatin of IC9 cells with micrococcal nuclease and DNase I showed a decreased nuclease sensitivity of the silent class I genes in comparison with active genes and the absence of DNase I hypersensitive sites in the promoter region of the silent Dk gene. These findings demonstrate that class I expression is turned off by a cis-acting regulatory mechanism at the level of the chromatin structure.

An active chromatin structure acquired by translocated c-myc genes

1986 ◽  
Vol 6 (4) ◽  
pp. 1357-1361
Author(s):  
E Kakkis ◽  
J Prehn ◽  
K Calame
Keyword(s):  
Chromatin Structure ◽  
Gene Segment ◽  
Dnase I ◽  
Regulatory Sequences ◽  
Active Chromatin ◽  
Alpha Gene

We used general sensitivity to DNase I digestion to analyze the chromatin structure of c-myc genes in seven murine plasmacytomas. In every case, the 3' portion of c-myc juxtaposed with C alpha displayed a much more DNase I-sensitive chromatin structure than untranslocated c-myc or, in one case analyzed, the reciprocally translocated 5' portion. Our data suggest the presence of regulatory sequences near the C alpha gene segment.

The chromatin structure of Saccharomyces cerevisiae autonomously replicating sequences changes during the cell division cycle

1991 ◽  
Vol 11 (10) ◽  
pp. 5301-5311
Author(s):  
J A Brown ◽  
S G Holmes ◽  
M M Smith
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Division ◽  
Chromatin Structure ◽  
Dnase I ◽  
S Phase ◽  
Cell Division Cycle ◽  
Characteristic Change ◽  
The Core ◽  
Dnase I Hypersensitive Sites ◽  
Hypersensitive Sites

The chromatin structures of two well-characterized autonomously replicating sequence (ARS) elements were examined at their chromosomal sites during the cell division cycle in Saccharomyces cerevisiae. The H4 ARS is located near one of the duplicate nonallelic histone H4 genes, while ARS1 is present near the TRP1 gene. Cells blocked in G1 either by alpha-factor arrest or by nitrogen starvation had two DNase I-hypersensitive sites of about equal intensity in the ARS element. This pattern of DNase I-hypersensitive sites was altered in synchronous cultures allowed to proceed into S phase. In addition to a general increase in DNase I sensitivity around the core consensus sequence, the DNase I-hypersensitive site closest to the core consensus became more nuclease sensitive than the distal site. This change in chromatin structure was restricted to the ARS region and depended on replication since cdc7 cells blocked near the time of replication initiation did not undergo the transition. Subsequent release of arrested cdc7 cells restored entry into S phase and was accompanied by the characteristic change in ARS chromatin structure.

Serum stimulation of the c-fos enhancer induces reversible changes in c-fos chromatin structure

1990 ◽  
Vol 10 (3) ◽  
pp. 1126-1133
Author(s):  
J L Feng ◽  
B Villeponteau
Keyword(s):  
Growth Factors ◽  
Dna Sequences ◽  
Chromatin Structure ◽  
Transcriptional Activity ◽  
Dnase I ◽  
Enhancer Activity ◽  
Serum Stimulation ◽  
Fos Protein ◽  
Dnase I Sensitivity ◽  
Stimulation Of

Transcription of the proto-oncogene c-fos is known to be activated by growth factors in serum and subsequently repressed by the Fos protein. We show that generalized DNase I sensitivity of c-fos chromatin correlates closely with enhancer activity during induction, repression, and superinduction of the c-fos gene. Within 90 s of serum stimulation, proximal DNA sequences on both sides of the enhancer exhibit increased DNase I sensitivity. Within 5 min, elevated DNase I sensitivity spreads to chromatin at the distal 3' end of the c-fos gene. These results suggest that an open state of chromatin is propagated in both directions from the enhancer. The induced alterations in chromatin structure precede the increased transcriptional activity of the c-fos gene, suggesting that these changes in chromatin structure potentiate transcription.

scholarly journals Major histocompatibility complex class I genes in murine fibrosarcoma IC9 are down regulated at the level of the chromatin structure.

1989 ◽  
Vol 9 (7) ◽  
pp. 3136-3142 ◽  
Author(s):  
U Maschek ◽  
W Pülm ◽  
S Segal ◽  
G J Hämmerling
Keyword(s):  
Major Histocompatibility Complex ◽  
Major Histocompatibility Complex Class ◽  
Chromatin Structure ◽  
Dnase I ◽  
Class I ◽  
Micrococcal Nuclease ◽  
Complex Class ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Nuclear Extracts

The fibrosarcoma IC9 is deficient in the expression of the major histocompatibility complex class I genes Kb, Kk, and Dk and expresses only the Db molecule. Because class I deficiency may enable tumor cells to escape the immune response by cytotoxic T lymphocytes, we investigated why the class I genes are not expressed. Expression of the silent class I genes could not be induced, but all known DNA-binding factors specific for class I genes could be detected in nuclear extracts of IC9 cells. After cloning of the silent Kb gene from the IC9 cells and subsequent transfection of this cloned Kb gene into LTK- and IC9 cells, normal Kb antigens were expressed on the cell surface of both cell lines. Digestion of the chromatin of IC9 cells with micrococcal nuclease and DNase I showed a decreased nuclease sensitivity of the silent class I genes in comparison with active genes and the absence of DNase I hypersensitive sites in the promoter region of the silent Dk gene. These findings demonstrate that class I expression is turned off by a cis-acting regulatory mechanism at the level of the chromatin structure.

Chromatin structure of a P-element-transduced hsp-28 gene in Drosophila melanogaster

1986 ◽  
Vol 6 (11) ◽  
pp. 4126-4129
Author(s):  
J C Eissenberg ◽  
S C Elgin
Keyword(s):  
Gene Expression ◽  
Drosophila Melanogaster ◽  
Chromatin Structure ◽  
Dnase I ◽  
P Element ◽  
Direct Selection ◽  
Wild Type ◽  
Dnase I Hypersensitive Sites ◽  
Hypersensitive Sites ◽  
Selection For

The Drosophila hsp-28 gene was heat inducible when transduced to novel chromosomal sites even when no direct selection for transduced gene expression was imposed. The pattern of DNase I-hypersensitive sites 5' to the wild type and transduced copy of hsp-28 was similar. In addition, DNase I-hypersensitive sites occurred within the P-element sequences flanking transduced loci.

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