Differential expression of nuclear HMG1, HMG2 proteins and H1⁰ histone in various blood cells

Abstract

Changes in the levels of chromosomal high-mobility group proteins HMG1, HMG2 and histone H1 zero were investigated in blood cells of various types, proliferation activity and stage of differentiation. The relative amounts of proteins HMG1, HMG2 and histone H1 zero were evaluated densitometrically by SDS-PAGE of 5 per cent w/v perchloric acid extracts of blood cells. Concerning the HMG1 and HMG2, the main conclusions were: the expression of these HMG proteins was higher in malignant cells, namely leukemia cell lines, then in lymphocytes or granulocytes and the distribution of HMG1 and HMG2 was highly cell-specific. In comparison with lymphoid cells, the levels of HMG1/2 were higher in myeloid cells. The results revealed that in myeloid cells HMG2 prevails over HMG1. There was no direct correlation between HMG1/2 expression and proliferation activity. The levels of HMG1/2 did not depend on the transcription of chromatin either. However, there was some connection between irreversibly differentiated nonproliferating cells and a loss of HMG1/2 proteins. Reversibly differentiated leukemic cells retain their HMG1/2 levels. Similarly to HMG1/2,H1 zero showed a strong cell specificity. The level of H1 zero was different in the various blood cell types. As compared with lymphoid cells, the level of H1 zero was several-fold higher in myeloid cells, regardless of whether they were normal or malignant. Moreover, there was an accumulation of H1 zero in differentiating HL-60 cells accompanied by only a slight decline in cell proliferation; this agrees with the idea that H1 zero expression is not directly associated with the inhibition of cell growth. Rather higher expression of H1 zero is related to changes during cell differentiation.

Hmgb3: an HMG-box family member expressed in primitive hematopoietic cells that inhibits myeloid and B-cell differentiation

“…HMGB1 and 2 have been shown to be expressed in all types of cells, but Hmgb3 represents the first example of an HMG-Box family member expressed in specific populations of hematopoietic cells. 24 Despite the fact that the relative stability of Hmgb3 protein compared to GFP is unknown, the data from our Hmgb3-KI mouse indicate that Hmgb3 expression can serve as a marker for most HSCs and CLPs. The pattern of Hmgb3 expression in myeloid progenitors is more complex.…”

Post-translational Methylation of High Mobility Group Box 1 (HMGB1) Causes Its Cytoplasmic Localization in Neutrophils

“…Perchloric acid (PCA) extract fractions were prepared from neutrophils and lymphocytes of human peripheral blood as described (13,17). Recombinant epitope-tagged, including 6ϫ histidine and Xpress tags, HMGB1 box A fragment B1A (amino acid residues 1-76, wt) and its mutants B1A-R23L (R23L), B1A-K27L (K27L), B1A-K28L (K28L), B1A-K29L (K29L), and B1A-K42L (K42L), and AlB fragment B1AlB (amino acid residues 1-164; box A ϩ linker ϩ box B, wt) and its mutants B1AlB-R23L (R23L), B1AlB-K27L (K27L), B1AlB-K28L (K28L), B1AlB-K29L (K29L), and B1AlB-K42L (K42L) were overexpressed in Escherichia coli JM109 cells transformed with the pTrcHisA plasmid carrying the corresponding cDNA sequences, and purified as described previously (15).…”

Effect of ulinastatin on the expression and distribution of high mobility group box 1 in human colon carcinoma cells in vitro

“…Compared with normal tissues, the HMGB1 protein is commonly overexpressed in gastric and colorectal adenocarcinoma (13). The HMGB1 protein is also upregulated in melanomas (14) and high levels of the protein are observed in leukemia cells (15). There is marked intertumoral variation in the expression of HMGB1 in different types of breast cancer (16).…”