Matrix nuclear

The native form of chromatin in cells assumes a higher order stmcture called the 30-nm filament, which adopts a solenoidal stmcture where the 10-nm filament is arranged in a left-handed cod (Fig. 5). The negative supercoiling of the DNA is manifested by writhing the hehcal axis around the nucleosomes. Chromatin stmcture is an example of toroidal winding whereas eukaryotic chromosomes are linear, the chromatin stmctures, attached to a nuclear matrix, define separate closed-circular topological domains. 

FIGURE 12.31 A model for chromosome structure, human chromosome 4. The 2-um DNA helix is wound twice around histone octamers to form 10-um uucleosomes, each of which contains 160 bp (80 per turn). These uucleosomes are then wound in solenoid fashion with six uucleosomes per turn to form a 30-nm filament. In this model, the 30-nm filament forms long DNA loops, each containing about 60,000 bp, which are attached at their base to the nuclear matrix. Eighteen of these loops are then wound radially around the circumference of a single turn to form a miniband unit of a chromosome. Approximately 10 of these minibands occur in each chromatid of human chromosome 4 at mitosis. 

Sachdev S, Bruhn L, Sieber H, et al (2001) PIASy, a nuclear matrix-associated SUMO E3 ligase, represses LEF1 activity by sequestration into nuclear bodies. Genes Dev 15 3088-3103... 

Dijkwel, P.A. and Wenink, P.W. (1986). Structural integrity of the nuclear matrix differential effects of thiol agents and metal chelators. J. Cell Sci. 84, 53-67. 

An elegant study of lycopene uptake in LNCaP, PC-3, and DU-145 cells using beadlet-delivered 1.48 J.M all-trans lycopene (a maximal level in human plasma) found that all three cell lines rapidly took up lycopene during the first 10 h of incubation. Cells continued to accrue lycopene, but more slowly, over the next 48h. The uptake by the LNCaP cells was 2.5-fold higher than PC-3 cells and 4.5-fold higher than DU-145 cells at 24h of incubation but lycopene showed no affinity for the AR receptor, which is expressed in the LNCaP cells (Liu et al. 2006). LNCaP uptake followed Michaelis-Menten kinetics with a V m i, of 66.3pmol/106 cells/h and a Km of 7.72 pM lycopene. Because of the sensitivity of their LC-MS-MS lycopene assay, Liu et al. were also able to investigate the subcellular lycopene distribution. The nuclear membrane contained 55%, the nuclear matrix 26%, and the microsomal fraction 19% of the intracellular fraction. The cytosol contained no lycopene(Liu et al. 2006). 

TEMPLATE AVAILABILITY The DNA template must be available. This may be controlled by DNA methylation, histone arrangement on the DNA, and interactions of the DNA with the nuclear matrix (a catch phrase for a bunch of protein that s always found in the nucleus). 

Cocco, L., Maraldi, N. M., and Manzoli, E. A., 1980, Phospholipid interactions in rat liver nuclear matrix. Biochem. Biophys. Res. Commun. 96 890-898. 

It has been assumed that the nucleus contains an immobile structure , in which chromatin fibers are partially attached and fixed. These structures are called nuclear matrix or nuclear scaffold . When cells are successively treated with detergent, high-salt solution and DNase I, the nuclear scaffold can be observed as a fibrous network in the cell nucleus (Fey et al, 1986 Nickerson, 2001 Yoshimura et al, 2003) (Fig. 2b). The biochemical analyses of the nuclear scaffold have identified a 174kDa protein as a major component (Fisher et al, 1982). This protein is now known as topo II (Berrios et al, 1985). 

Berrios M, Osheroff N, Fisher PA (1985) In situ localization of DNA topoisomerase 11, a major polypeptide component of the Drosophila nuclear matrix fraction. Proc Natl Acad Sci USA... 

Burlde A (2005) Poly(ADP-ribose). The most elaborate metabolite of NAD. Febs J 272 4576-4589 Burlde A, Brabeck C, Diefenbach J, Beneke S (2005) The emerging role of poly(ADP-ribose) polymerase-1 in longevity. Int J Biochem Cell Biol 37 1043—1053 Cardenas-Corona M, Jacobson E, Jacobson M (1987) Endogenous polymers of ADP-ribose are associated with the nuclear matrix. J Biol Chem 262 14863—14866 Chang P, Jacobson MK, Mitchison TJ (2004) Poly(ADP-ribose) is required for spindle assembly and structure. Nature 432 645-649... 

Gotzmann J, Eger A, Meissner M, Grimm R, Gerner C, Sauermann G, Foisner R (1997) Two-dimensional electrophoresis reveals a nuclear matrix-associated nucleolin complex of basic isoelectric point [In Process Citation]. Electrophoresis 18 2645-2653... 

Muenchen HJ, Pienta KJ (1999) The role of the nuclear matrix in cancer chemotherapy. Crit Rev Eukaryot Gene Expr 9(3 ) 337-343... 

Berezney R, Buchholtz LA (1981) Dynamic association of repheating DNA fragments with the nuclear matrix of regenerating hver. Exp Cell Res 132(1) 1-13 Berezney R, Coffey DS (1974) Identification of a nuclear protein matrix. Biochem Biophys Res Commun 60(4) 1410-1417... 

Berezney R, Coffey DS (1977) Nuclear matrix, isolation and characterization of a framework structure from rat liver nuclei. J Cell Biol 73(3) 616-637... 

Forrester WC, van Genderen C, Jenuwein T, Grosschedl R (1994) Dependence of enhancer-mediated transcription of the immunoglobulin mu gene on nuclear matrix attachment regions. Science 265(5176) 1221-1225... 

Khanuja PS, Lehr JE, Soule HD, Gehani SK, Noto AC, Choudhury S, Chen R, Pienta KJ (1993) Nuclear matrix proteins in normal and breast cancer cells. Cancer Res 53(14) 3394-3398 Konety BR, Nangia AK, Nguyen T.S, Veitmeier BN, Dhir R, Acierno JS, Becich MJ, Hrebinko RL, Getzenberg RH (1998) Identification of nuclear matrix protein alterations associated with renal cell carcinoma. J Urol 159(4) 1359-1363... 

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