scholarly journals Changes in quantities of high-mobility-group protein 1 in oviduct cellular fractions after oestrogen stimulation

1981 ◽  
Vol 198 (1) ◽  
pp. 85-90 ◽  
Author(s):  
C T Teng ◽  
C S Teng
Keyword(s):  
Microsomal Fraction ◽  
High Mobility ◽  
Quantitative Change ◽  
High Mobility Group ◽  
Nuclear Fraction ◽  
Hmg Proteins ◽  
High Mobility Group Protein ◽  
Group Protein ◽  
Oviduct Cell

Antiserum against chick oviduct high-mobility-group protein 1 (HMG 1) has been induced in the rabbit. With this antiserum, immunobiochemical techniques have been used to probe the quantitative change of HMG 1 in the cellular fractions of chick oviduct before or after oestrogen stimulation. HMG 1 is detectable in the cytosol, microsomal and nuclear fraction of the chick oviduct cell. After administration of oestrogen to young chicks in vivo for 5 days, the quantity of HMG 1 is increased 4-fold in the cytosol, 3.5-fold in the microsomal fraction and 1.6-fold in the nuclear fraction. The finding of large amounts of HMG 1 in cytoplasm of oviduct cell is not likely due to its leakage from the nucleus. We anticipate that HMG 1 is synthesized in the cytoplasm and then transported into the nucleus. The synthesis and transportation of HMG proteins is probably regulated by oestrogen.

Preferential Phosphorylation of High Mobility Group Protein 17 in vitro by a Nuclear Protein Kinase

1981 ◽  
Vol 36 (3-4) ◽  
pp. 319-322 ◽  
Keyword(s):  
Nuclear Protein ◽  
High Mobility ◽  
High Specificity ◽  
High Mobility Group ◽  
Hmg Proteins ◽  
High Mobility Group Protein ◽  
High Preference ◽  
Group Protein

The ability of the high mobility group proteins (HMG-1,2,14 and 17) to serve as substrate for protein kinases was investigated by incubating them with a cytoplasmic and nuclear kinase. In both cases phosphate was incorporated into all four HMG proteins. The amount of phosphate incorporated and the specificity for the four proteins was quite different for the two kinases. Whereas the cytoplasmic kinase phosphorylated the HMG-1 and 2 to a higher degree than HMG-14 and 17, the nuclear kinase exhibited a high specificity for the HMG -17, leaving the other three proteins with only a small amount. The high preference of a nuclear kinase for HMG-17 may be indicative of a specific phosphorylation occuring also in vivo

scholarly journals Intra- and intermolecular cooperative binding of high-mobility-group protein I(Y) to the beta-interferon promoter.

1997 ◽  
Vol 17 (7) ◽  
pp. 3649-3662 ◽  
Author(s):  
J Yie ◽  
S Liang ◽  
M Merika ◽  
D Thanos
Keyword(s):  
Protein Interactions ◽  
Binding Sites ◽  
Specific Binding ◽  
High Mobility ◽  
High Mobility Group ◽  
High Mobility Group Protein ◽  
Beta Interferon ◽  
Eukaryotic Genes ◽  
Group Protein

The mammalian high-mobility-group protein I(Y) [HMG I(Y)], while not a typical transcriptional activator, is required for the expression of many eukaryotic genes. HMG I(Y) appears to recruit and stabilize complexes of transcriptional activators through protein-DNA and protein-protein interactions. The protein binds to the minor groove of DNA via three short basic repeats, preferring tracts of adenines and thymines arranged on the same face of the DNA helix. However, the mode by which these three basic repeats function together to recognize HMG I(Y) binding sites has remained unclear. Here, using deletion mutants of HMG I(Y), DNase I footprinting, methylation interference, and in vivo transcriptional assays, we have characterized the binding of HMG I(Y) to the model beta-interferon enhancer. We show that two molecules of HMG I(Y) bind to the enhancer in a highly cooperative fashion, each molecule using a distinct pair of basic repeats to recognize the tandem AT-rich regions of the binding sites. We have also characterized the function of each basic repeat, showing that only the central repeat accounts for specific DNA binding and that the presence of a second repeat bound to an adjacent AT-rich region results in intramolecular cooperativity in binding. Surprisingly, the carboxyl-terminal acidic tail of HMG I(Y) is also important for specific binding in the context of the full-length protein. Our results present a detailed examination of HMG I(Y) binding in an important biological context, which can be extended not only to HMG I(Y) binding in other systems but also to the binding mode of many other proteins containing homologous basic repeats, which have been conserved from bacteria to humans.

High-mobility group protein HMGB2 regulates human erythroid differentiation through trans-activation of GFI1B transcription

Blood ◽  
2010 ◽  
Vol 115 (3) ◽  
pp. 687-695 ◽  
Author(s):  
Benoît Laurent ◽  
Voahangy Randrianarison-Huetz ◽  
Vincent Maréchal ◽  
Patrick Mayeux ◽  
Isabella Dusanter-Fourt ◽  
...  
Keyword(s):  
High Mobility ◽  
Erythroid Differentiation ◽  
High Mobility Group ◽  
Hematopoietic Progenitor Cells ◽  
Hematopoietic Progenitor ◽  
High Mobility Group Protein ◽  
Group Protein ◽  
Hmg Protein ◽  
Embryonic Death

Abstract Gfi-1B is a transcriptional repressor that is crucial for erythroid differentiation: inactivation of the GFI1B gene in mice leads to embryonic death due to failure to produce differentiated red cells. Accordingly, GFI1B expression is tightly regulated during erythropoiesis, but the mechanisms involved in such regulation remain partially understood. We here identify HMGB2, a high-mobility group HMG protein, as a key regulator of GFI1B transcription. HMGB2 binds to the GFI1B promoter in vivo and up-regulates its trans-activation most likely by enhancing the binding of Oct-1 and, to a lesser extent, of GATA-1 and NF-Y to the GFI1B promoter. HMGB2 expression increases during erythroid differentiation concomitantly to the increase of GfI1B transcription. Importantly, knockdown of HMGB2 in immature hematopoietic progenitor cells leads to decreased Gfi-1B expression and impairs their erythroid differentiation. We propose that HMGB2 potentiates GATA-1–dependent transcription of GFI1B by Oct-1 and thereby controls erythroid differentiation.

scholarly journals Detection of monoclonal antibody to high-mobility-group protein 17 from chick oviduct

1982 ◽  
Vol 203 (2) ◽  
pp. 471-476 ◽  
Author(s):  
C S Teng ◽  
C T Teng ◽  
T S Chan
Keyword(s):  
Solid Phase ◽  
Protein A ◽  
High Mobility ◽  
High Mobility Group ◽  
Chromosomal Protein ◽  
Hmg Proteins ◽  
High Mobility Group Protein ◽  
Group Protein ◽  
Solid Phase Radioimmunoassay ◽  
Hmg Protein

Total chromosomal HMG (high-mobility-group) proteins have been isolated from oestrogen-stimulated chick oviduct. The antibodies against these proteins were induced in mice and subsequently their spleen cells were fused with myeloma cells to form hybridomas. A highly purified HMG protein, 17, was used to select for the hybridomas that produce antibody against HMG protein 17. The hybridomas were cultured and injected into mice to produce ascites. The antibody against HMG protein 17 in the IgG (immunoglobulin G) fraction of the ascites fluid was obtained by Protein A-Sepharose column chromatography. We have devised a solid-phase radioimmunoassay and enzyme-linked serological assay for the detection and characterization of this antibody directed against HMG protein 17. This anti-(HMG protein 17) IgG interacted only with HMG protein 17, but not with other chromosomal proteins, e.g. histone H1, ‘95K protein’ (a chick oviduct-specific chromosomal protein) and HMG proteins 1, 2 and 14. The monospecific nature of this anti-(HMG protein 17) IgG fraction is confirmed.

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