scholarly journals Characterization and chromatin distribution of the H1 histones and high-mobility-group non-histone chromosomal proteins of trout liver and hepatocellular carcinoma

1991 ◽  
Vol 280 (2) ◽  
pp. 491-497 ◽  
Author(s):  
J R Davie ◽  
G P Delcuve
Keyword(s):  
Gene Expression ◽  
Hepatocellular Carcinoma ◽  
High Mobility ◽  
High Mobility Group ◽  
Hmg Proteins ◽  
Chromosomal Proteins ◽  
H1 Histone ◽  
Liver Chromatin ◽  
And Function ◽  
Liver Hepatocellular Carcinoma

The H1 histones serve as general repressors of gene expression by inducing the formation of a compact chromatin structure, whereas the high-mobility-group (HMG) non-histone chromosomal proteins have roles in maintaining the structure and function of transcriptionally active chromatin. The distribution of the H1 histone subtypes and HMG proteins among various trout tissues (liver, hepatocellular carcinoma, testis and erythrocyte) was determined. Histone H1b was present in the chromatin of liver, but not in the chromatin of hepatocellular carcinoma, testis or erythrocyte. Nuclease-resistant regions of liver chromatin had elevated levels of histone H1b. Histone H1b was isolated, and the N-terminal amino acid sequence of histone H1b was found to be highly similar to that of mammalian histone H1(0) and duck H5. HMG proteins T1, T2, T3, H6, C, D and F were associated with liver and hepatocellular-carcinoma chromatin, with hepatocellular carcinoma containing higher levels of HMG T1 and F. Testis and erythrocyte had HMG T2 and H6 as their predominant HMG proteins. Most of the HMG H6 of hepatocellular carcinoma, but not of liver, was located in a chromatin fraction that was soluble at physiological ionic strength and enriched in transcriptionally active DNA. These alterations in the chromatin distribution and content of hepatocyte HMG proteins and H1 histone subtypes may contribute to aberrant hepatocyte gene expression in the hepatocellular carcinoma.

scholarly journals Macronuclei and micronuclei in Tetrahymena thermophila contain high-mobility-group-like chromosomal proteins containing a highly conserved eleven-amino-acid putative DNA-binding sequence.

1991 ◽  
Vol 11 (1) ◽  
pp. 166-174 ◽  
Author(s):  
I G Schulman ◽  
T Wang ◽  
M Wu ◽  
J Bowen ◽  
R G Cook ◽  
...  
Keyword(s):  
Amino Acid ◽  
Dna Binding ◽  
Tetrahymena Thermophila ◽  
High Mobility ◽  
Amino Acid Sequences ◽  
High Mobility Group ◽  
Binding Motif ◽  
Hmg Proteins ◽  
Chromosomal Proteins ◽  
Conserved Sequence

HMG (high-mobility-group protein) B and HMG C are abundant nonhistone chromosomal proteins isolated from Tetrahymena thermophila macronuclei with solubilities, molecular weights, and amino acid compositions like those of vertebrate HMG proteins. Genomic clones encoding each of these proteins have been sequenced. Both are single-copy genes that encode single polyadenylated messages whose amounts are 10 to 15 times greater in growing cells than in starved, nongrowing cells. The derived amino acid sequences of HMG B and HMG C contain a highly conserved sequence, the HMG 1 box, found in vertebrate HMGs 1 and 2, and we speculate that this sequence may represent a novel, previously unrecognized DNA-binding motif in this class of chromosomal proteins. Like HMGs 1 and 2, HMGs B and C contain a high percentage of aromatic amino acids. However, the Tetrahymena HMGs are small, are associated with nucleosome core particles, and can be specifically extracted from macronuclei by elutive intercalation, properties associated with vertebrate HMGs 14 and 17, not HMGs 1 and 2. Thus, it appears that these Tetrahymena proteins have features in common with both of the major subgroups of higher eucaryotic HMG proteins. Surprisingly, a linker histone found exclusively in transcriptionally inactive micronuclei also has several HMG-like characteristics, including the ability to be specifically extracted from nuclei by elutive intercalation and the presence of the HMG 1 box. This finding suggests that at least in T. thermophila, proteins with HMG-like properties are not restricted to regions of transcriptionally active chromatin.

scholarly journals Comparison of the high-mobility-group chromosomal proteins in rainbow-trout (Salmo gairdnerii) liver and testis

1983 ◽  
Vol 215 (3) ◽  
pp. 531-538 ◽  
Author(s):  
E Brown ◽  
G H Goodwin
Keyword(s):  
Rainbow Trout ◽  
High Mobility ◽  
High Mobility Group ◽  
Hmg Proteins ◽  
Chromosomal Proteins ◽  
Main Fraction ◽  
T1 And T2 ◽  
Protein F

Chromatography and characterization of the proteins extracted by 5% (w/v) HClO4 from rainbow-trout (Salmo gairdnerii) liver and testis show that the two tissues present a characteristically different spectrum of high-mobility-group (HMG) proteins. A variant subfraction of HMG C is found in liver, but is not detectable in testis, where even the main fraction of HMG C is present in only very low quantity. A protein, F, which appears to be related to protein H6 has similarly been isolated only from liver and not from testis. Quantification of the HMG proteins in total 5%-HClO4 extracts of trout liver and testis nuclei shows that, in relation to DNA, levels of HMG T1 and T2, and D are more than 2-fold, and C, 20-fold higher in liver than in testis. However, these differences do not result merely from the sequential withdrawal of HMG proteins at the same time that histones are replaced by protamines in the developing spermatid, since in testis, at some stages of maturation, levels of H6 are almost 2-fold higher than in liver. The implications of these findings for the function of HMG proteins are discussed.

Macronuclei and micronuclei in Tetrahymena thermophila contain high-mobility-group-like chromosomal proteins containing a highly conserved eleven-amino-acid putative DNA-binding sequence

1991 ◽  
Vol 11 (1) ◽  
pp. 166-174
Author(s):  
I G Schulman ◽  
T Wang ◽  
M Wu ◽  
J Bowen ◽  
R G Cook ◽  
...  
Keyword(s):  
Amino Acid ◽  
Dna Binding ◽  
Tetrahymena Thermophila ◽  
High Mobility ◽  
Amino Acid Sequences ◽  
High Mobility Group ◽  
Binding Motif ◽  
Hmg Proteins ◽  
Chromosomal Proteins ◽  
Conserved Sequence

HMG (high-mobility-group protein) B and HMG C are abundant nonhistone chromosomal proteins isolated from Tetrahymena thermophila macronuclei with solubilities, molecular weights, and amino acid compositions like those of vertebrate HMG proteins. Genomic clones encoding each of these proteins have been sequenced. Both are single-copy genes that encode single polyadenylated messages whose amounts are 10 to 15 times greater in growing cells than in starved, nongrowing cells. The derived amino acid sequences of HMG B and HMG C contain a highly conserved sequence, the HMG 1 box, found in vertebrate HMGs 1 and 2, and we speculate that this sequence may represent a novel, previously unrecognized DNA-binding motif in this class of chromosomal proteins. Like HMGs 1 and 2, HMGs B and C contain a high percentage of aromatic amino acids. However, the Tetrahymena HMGs are small, are associated with nucleosome core particles, and can be specifically extracted from macronuclei by elutive intercalation, properties associated with vertebrate HMGs 14 and 17, not HMGs 1 and 2. Thus, it appears that these Tetrahymena proteins have features in common with both of the major subgroups of higher eucaryotic HMG proteins. Surprisingly, a linker histone found exclusively in transcriptionally inactive micronuclei also has several HMG-like characteristics, including the ability to be specifically extracted from nuclei by elutive intercalation and the presence of the HMG 1 box. This finding suggests that at least in T. thermophila, proteins with HMG-like properties are not restricted to regions of transcriptionally active chromatin.

scholarly journals Identification of glycolysis related pathways in pancreatic adenocarcinoma and liver hepatocellular carcinoma based on TCGA and GEO datasets

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ji Li ◽  
Chen Zhu ◽  
Peipei Yue ◽  
Tianyu Zheng ◽  
Yan Li ◽  
...  
Keyword(s):  
Gene Expression ◽  
Hepatocellular Carcinoma ◽  
Energy Metabolism ◽  
Pancreatic Adenocarcinoma ◽  
Digestive System ◽  
Prognostic Significance ◽  
R Package ◽  
The Cancer Genome Atlas ◽  
System Structure ◽  
Liver Hepatocellular Carcinoma

Abstract Background Abnormal energy metabolism is one of the characteristics of tumor cells, and it is also a research hotspot in recent years. Due to the complexity of digestive system structure, the frequency of tumor is relatively high. We aim to clarify the prognostic significance of energy metabolism in digestive system tumors and the underlying mechanisms. Methods Gene set variance analysis (GSVA) R package was used to establish the metabolic score, and the score was used to represent the metabolic level. The relationship between the metabolism and prognosis of digestive system tumors was explored using the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Volcano plots and gene ontology (GO) analyze were used to show different genes and different functions enriched between different glycolysis levels, and GSEA was used to analyze the pathway enrichment. Nomogram was constructed by R package based on gene characteristics and clinical parameters. qPCR and Western Blot were applied to analyze gene expression. All statistical analyses were conducted using SPSS, GraphPad Prism 7, and R software. All validated experiments were performed three times independently. Results High glycolysis metabolism score was significantly associated with poor prognosis in pancreatic adenocarcinoma (PAAD) and liver hepatocellular carcinoma (LIHC). The STAT3 (signal transducer and activator of transcription 3) and YAP1 (Yes1-associated transcriptional regulator) pathways were the most critical signaling pathways in glycolysis modulation in PAAD and LIHC, respectively. Interestingly, elevated glycolysis levels could also enhance STAT3 and YAP1 activity in PAAD and LIHC cells, respectively, forming a positive feedback loop. Conclusions Our results may provide new insights into the indispensable role of glycolysis metabolism in digestive system tumors and guide the direction of future metabolism–signaling target combined therapy.

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