Nuclear matrix proteins specific for subtypes of human hematopoietic cells

Abstract

Nuclear matrices were prepared from isolated subtypes of human hematopoietic cells and from cultured leukemia cells. The nuclear matrix proteins were analyzed by high-resolution two-dimensional gel electrophoresis and computer-assisted image analysis. While more than 200 protein spots were shared among the cells, about 50 distinct spots were found characteristic for individual cells or groups of related cells. This allowed to differentiate between hematopoietic cells and nonhematopoietic cells, lymphocytes and myeloid cells, monocytes, neutrophils, and promyelocytic leukemia cells. B and T lymphocytes could not be differentiated. Myeloid cells with their polymorph nuclei were characterized by the presence of 13 and by the absence of seven distinct spots, as well as by low concentrations of nuclear lamins and of heterogeneous nuclear ribonucleoproteins. Neutrophils with multilobular nuclei displayed six additional spots, while lacking 18 nuclear matrix protein spots. The nuclear matrix of proliferating cells showed three distinct spots in addition to proliferating cell nuclear antigen, increased concentrations of numatrin (B23), and heterogeneous nuclear ribonucleoproteins. The described cell-specific nuclear matrix proteins may represent new markers for hematopoietic cells.

Human Pso4 Is a Metnase (SETMAR)-binding Partner That Regulates Metnase Function in DNA Repair

“…Pso4 is a part of the pre-mRNA splicing complex consisting of Pso4, Cdc5L, Plrg1, and Spf27 (17) and has been previously linked to DNA repair through a direct physical interaction between Cdc5L and WRN, the protein deficient in Werner syndrome (18). Human Pso4 contains six successive WD-40 motifs at the C terminus that is known to form a structural interface for the assembly of multiprotein complexes (19) and has been identified as a component of the nuclear matrix (20). Pso4 is also a U-box protein with associated E3 ubiquitin ligase activity crucial for its function in pre-mRNA splicing in vivo (21)(22)(23).…”

“…Specific role(s) for Pso4 in DSB repair is not known; however, it has been identified as a component of the nuclear matrix (20). Although hPso4 is a direct binding partner of Metnase, our immunoprecipitation of Metnase experiment also pulled down the human homolog of Spf27, a member of the Prp19 core complex involved in pre-mRNA splicing.…”

Proteome analysis of nuclear matrix proteins during apoptotic chromatin condensation

“…In a previous study we have compared the NMPs of these cells with those of monocytes and lymphocytes isolated from peripheral blood and have described the lack of otherwise abundant and ubiquitously occurring NMPs in these cells. 4 Intriguingly, most of these NMPs were identical with those found to decrease or disappear in other cells during ACC (not shown). On the other hand, all of the NMPs apparently maintained during ACC were found still detectable in neutrophils (not shown).…”

Reorganization of nuclear factors during myeloid differentiation

“…Stein et al [1996] concluded that the structural modi®ca-tions associated with proliferation and gene expression during differentiation are accommodated by the constituents of the nuclear matrix. Many of these proteins, such as certain hnRNPs and lamins, have recently been shown by highresolution 2D gel electrophoresis to be absent in mature granulocytes and present in other hemopoietic cells [Gerner and Sauermann, 1999]. Thus, we conclude that the distribution of PSF-rich foci during different points of hemopoietic differentiation from the stem cell level, through progenitors and intermediately differentiated cells, up to fully differentiated specialized cells is dynamic and correlates with the transcriptional state of all these stages.…”