scholarly journals Identification of two Sox17 messenger RNA isoforms, with and without the high mobility group box region, and their differential expression in mouse spermatogenesis.

1996 ◽  
Vol 133 (3) ◽  
pp. 667-681 ◽  
Author(s):  
Y Kanai ◽  
M Kanai-Azuma ◽  
T Noce ◽  
T C Saido ◽  
T Shiroishi ◽  
...  
Keyword(s):  
Amino Acids ◽  
Dna Binding ◽  
Reporter Gene ◽  
Germ Cells ◽  
Messenger Rna ◽  
High Mobility ◽  
The Other ◽  
High Mobility Group ◽  
Luciferase Reporter ◽  
Mrna Isoforms

The different mRNA isoforms of the mouse Sox17 gene were isolated from adult mouse testis cDNAs. One form (referred to as form Sox17) encodes an Sry-related protein of 419 amino acids containing a single high mobility group box near the NH2-terminus, while the other form (referred to as form t-Sox17) shows a unique mRNA isoform of the Sox17 gene with a partial deletion of the HMG box region. Analysis of genomic DNA revealed that these two isoforms were produced at least by alternative splicing of the exon corresponding to the 5' untranslated region and NH2-terminal 102 amino acids. RNA analyses in the testis revealed that form Sox17 began at the pachytene spermatocyte stage and was highly accumulated in round spermatids. Protein analyses revealed that t-Sox17 isoforms, as well as Sox17 isoforms, were translated into the protein products in the testis, although the amount of t-Sox17 products is lower in comparison to the high accumulation of t-Sox17 mRNA. By the electrophoretic mobility-shift assay and the random selection assay using recombinant Sox17 and t-Sox17 proteins, Sox17 protein is a DNA-binding protein with a similar sequence specificity to Sry and the other members of Sox family proteins, while t-Sox17 shows no apparent DNA-binding activity. Moreover, by a cotransfection experiment using a luciferase reporter gene, Sox17 could stimulate transcription through its binding site, but t-Sox17 had little effect on reporter gene expression. Thus, these findings suggest that Sox17 may function as a transcriptional activator in the premeiotic germ cells, and that a splicing switch into t-Sox17 may lead to the loss of its function in the postmeiotic germ cells.

scholarly journals Mutagenesis of the HMGB (high-mobility group B) protein Cmb1 (cytosine-mismatch binding 1) of Schizosaccharomyces pombe: effects on recognition of DNA mismatches and damage

2003 ◽  
Vol 372 (2) ◽  
pp. 651-660 ◽  
Author(s):  
Christophe KUNZ ◽  
Karin ZURBRIGGEN ◽  
Oliver FLECK
Keyword(s):  
Amino Acids ◽  
Dna Binding ◽  
Schizosaccharomyces Pombe ◽  
Excision Repair ◽  
Specific Binding ◽  
High Mobility ◽  
High Mobility Group ◽  
Dna Mismatches ◽  
Terminal Amino ◽  
Group B

Cmb1 (cytosine-mismatch binding 1) is a high-mobility group (HMG) protein of Schizosaccharomyces pombe, which consists of 223 amino acids and has a single HMG domain at the C-terminal end. We have created several mutant and deletion forms of the Cmb1 protein and studied the effects on general DNA binding and specific binding to DNA mismatches and damaged DNA. Cmb1Δ41 (i.e. Cmb1 from which the 41 N-terminal amino acids have been deleted) bound specifically to cytosine-containing mismatches, to the cisplatin-induced intrastrand cross-links cis-GG and cis-AG and to an O6-methylguanine lesion. DNA binding was not affected when the 45 N-terminal amino acids were deleted, but was abolished in the absence of the 50 N-terminal amino acids, and was reduced when Cmb1 was truncated by between five and eleven C-terminal amino acids. Cmb1, both with and without the C-terminal truncations, retained its DNA binding affinity after heating at 95 °C. The cmb1 gene was induced when S. pombe cells were treated with cisplatin. Mitotic mutation rates were increased in a S. pombe cmb1 null mutant and in a cmb1-(1–212) mutant, which encodes a Cmb1 protein lacking the 11 C-terminal amino acids. We conclude that mutation avoidance by Cmb1 is distinct from Msh2-dependent mismatch repair, but related to nucleotide excision repair.

Comparative analysis of the influence of the high-mobility group box 1 protein on DNA binding and transcriptional activation by the androgen, glucocorticoid, progesterone and mineralocorticoid receptors

2001 ◽  
Vol 361 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Guy VERRIJDT ◽  
Annemie HAELENS ◽  
Erik SCHOENMAKERS ◽  
Wilfried ROMBAUTS ◽  
Frank CLAESSENS
Keyword(s):  
Androgen Receptor ◽  
Comparative Analysis ◽  
Dna Binding ◽  
Mineralocorticoid Receptor ◽  
Hormone Receptors ◽  
Steroid Hormone ◽  
High Mobility ◽  
Steroid Hormone Receptors ◽  
High Mobility Group ◽  
Mineralocorticoid Receptors

We performed a comparative analysis of the effect of high-mobility group box protein 1 (HMGB1) on DNA binding by the DNA-binding domains (DBDs) of the androgen, glucocorticoid, progesterone and mineralocorticoid receptors. The affinity of the DBDs of the different receptors for the tyrosine aminotransferase glucocorticoid response element, a classical high-affinity binding element, was augmented up to 7-fold by HMGB1. We found no major differences in the effects of HMGB1 on DNA binding between the different steroid hormone receptors. In transient transfection assays, however, HMGB1 significantly enhances the activity of the glucocorticoid and progesterone receptors but not the androgen or mineralocorticoid receptor. We also investigated the effect of HMGB1 on the binding of the androgen receptor DBD to a subclass of directly repeated response elements that is recognized exclusively by the androgen receptor and not by the glucocorticoid, progesterone or mineralocorticoid receptor. Surprisingly, a deletion of 26 amino acid residues from the C-terminal extension of the androgen receptor DBD does not influence DNA binding but destroys its sensitivity to HMGB1. Deletion of the corresponding fragment in the DBDs of the glucocorticoid, progesterone and mineralocorticoid receptor destroyed their DNA binding. This 26-residue fragment is therefore essential for the influence of HMGB1 on DNA recognition by all steroid hormone receptors that were tested. However, it is dispensable for DNA binding by the androgen receptor.

scholarly journals The High Mobility Group Protein 1 Enhances Binding of the Estrogen Receptor DNA Binding Domain to the Estrogen Response Element

1998 ◽  
Vol 12 (5) ◽  
pp. 664-674 ◽  
Author(s):  
Lorene E. Romine ◽  
Jennifer R. Wood ◽  
LuAnne A. Lamia ◽  
Paul Prendergast ◽  
Dean P. Edwards ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Dna Binding ◽  
High Mobility ◽  
High Mobility Group ◽  
Estrogen Response Element ◽  
Dna Binding Domain ◽  
High Mobility Group Protein ◽  
Response Element ◽  
Estrogen Response ◽  
Group Protein

Abstract We have examined the ability of the high-mobility group protein 1 (HMG1) to alter binding of the estrogen receptor DNA-binding domain (DBD) to the estrogen response element (ERE). HMG1 dramatically enhanced binding of purified, bacterially expressed DBD to the consensus vitellogenin A2 ERE in a dose-dependent manner. The ability of HMG1 to stabilize the DBD-ERE complex resulted in part from a decrease in the dissociation rate of the DBD from the ERE. Antibody supershift experiments demonstrated that HMG1 was also capable of forming a ternary complex with the ERE-bound DBD in the presence of HMG1-specific antibody. HMG1 did not substantially affect DBD-ERE contacts as assessed by methylation interference assays, nor did it alter the ability of the DBD to induce distortion in ERE-containing DNA fragments. Because HMG1 dramatically enhanced estrogen receptor DBD binding to the ERE, and the DBD is the most highly conserved region among the nuclear receptor superfamily members, HMG1 may function to enhance binding of other nuclear receptors to their respective response elements and act in concert with coactivator proteins to regulate expression of hormone-responsive genes.

Expression of High Mobility Group Box Chromosomal Protein 1 and Its Modulating Effects on Downstream Cytokines in Systemic Lupus Erythematosus

2010 ◽  
Vol 37 (4) ◽  
pp. 766-775 ◽  
Author(s):  
JIE LI ◽  
HONGFU XIE ◽  
TING WEN ◽  
HONGBO LIU ◽  
WU ZHU ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Disease Activity ◽  
Lupus Erythematosus ◽  
Messenger Rna ◽  
Activity Index ◽  
High Mobility ◽  
High Mobility Group ◽  
Chromosomal Protein ◽  
Systemic Lupus ◽  
Tnf Α

Objective.To compare the expression of high mobility group box chromosomal protein 1 (HMGB1) and the modulating effects on its downstream cytokines in patients with systemic lupus erythematosus (SLE) and healthy controls.Methods.HMGB1 concentrations in serum from SLE patients and controls were measured by immunoblot analysis. HMGB1 messenger RNA (mRNA) expression in peripheral blood mononuclear cells (PBMC) was detected by real-time reverse transcription–polymerase chain reaction. Immunofluorescence assay was employed to examine the translocation of HMGB1 in monocytes after endotoxin stimulation. Release of tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6) by PBMC after rHMGB1 stimulation was also measured.Results.Serum HMGB1 levels and HMGB1 mRNA expressions in PBMC were elevated in SLE patients compared with controls. A positive correlation was demonstrated between HMGB1 concentrations and SLE Disease Activity Index. There was an inverse correlation between HMGB1 levels and C4 and C3 concentrations in SLE patients. HMGB1 concentrations were higher in patients with vasculitis and myositis. Lipopolysaccharide stimulated a temporarily elevated release of HMGB1 in SLE patients compared with controls. The pattern and localization of HMGB1 staining in monocytes were similar in both groups. After stimulation with rHMGB1, TNF-α level decreased but IL-6 level increased in SLE patients compared with controls.Conclusion.Our findings suggest that increased serum levels of HMGB1 in SLE may be associated with lupus disease activity. The altered production of TNF-α and IL-6 in response to rHMGB1 stimulation may participate in the disruption of cytokine homeostasis in SLE.

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