Chromosome function

The centromere–kinetochore complex is a highly specialized chromatin domain that both mediates and monitors chromosome–spindle interactions responsible for accurate partitioning of sister chromatids to daughter cells. Centromeres are distinguished from adjacent chromatin by specific patterns of histone modification and the presence of a centromere-specific histone H3 variant (e.g. CENP-A). Centromere-proximal regions usually correspond to sites of avid and persistent sister chromatid cohesion mediated by the conserved cohesin complex.

15p research12 01-06-2013 49 4   Download

Mammalian alcohol dehydrogenases (ADH) 3 form a com-plex enzyme system based on amino-acid sequence, func-tional properties, and gene expression pattern. At least four mouseAdhgenes are known to encode di€erent enzyme classes that share less than 60% amino-acid sequence iden-tity. Two ADH-containing and overlapping C57BL/6 bacterial arti®cial chromosome clones, RP23-393J8 and -463H24, were identi®ed in a library screen, physically mapped, and sequenced.

9p research12 29-04-2013 21 2   Download

BLASTanalysis of the human and mouse genome sequence databases using the sequence of the human CMP-sialic acid:b-galactoside a-2,6-sialyltransferase cDNA (hST6Gal I, EC2.4.99.1) as a probe allowed us to identify a putative sialyltransferase gene on chromosome 2. The sequence of the corresponding cDNA was also found as an expressed sequence tag of human brain.

12p tumor12 20-04-2013 27 2   Download

There are at least two membrane-bound (HynSL and HupSL) and one soluble (HoxEFUYH) [NiFe]hydrogen-ases in Thiocapsa roseopersicinaBBS, a purple sulfur photosynthetic bacterium. Genes coding for accessory pro-teins that participate in the biosynthesis and maturation of hydrogenases seem to be scattered along the chromosome. Transposon-based mutagenesis was used to locate the hydrogenase accessory genes.

10p fptmusic 16-04-2013 33 3   Download

Analysis of a draft nuclear genome sequence of the diatomThalassiosira pseudonana revealed the presence of 11 open reading frames showing significant similarity to functionally characterized fatty acid front-end desaturases. The corresponding genes occupy discrete chromosomal loca-tions as determined by comparison with the recently published genome sequence. Phylogenetic analysis showed that two of the T. pseudonana desaturase (Tpdes) sequences grouped with proteobacterial desaturases that lack a fused cytochrome b5 domain. ...

12p fptmusic 11-04-2013 32 2   Download

Malate dehydrogenase (MDH) may be important in car-bohydrate and energymetabolism inmalarial parasites. The cDNA corresponding to the MDHgene, identified on chromosome 6 of thePlasmodium falciparumgenome, was amplified by RT-PCR, cloned and overexpressed in Escherichia coli. The recombinant PfMDH was purified to homogeneity and biochemically characterized as an NAD + (H)-specific MDH, which catalysed reversible inter-conversion of malate to oxaloacetate.

15p awards 05-04-2013 77 7   Download

The ESSS protein is a recently identified subunit of mam-malian mitochondrial complex I. It is a relatively small integral membrane protein (122 amino acids) found in the b-subcomplex. Genomic sequence database searches reveal its localization to theX-chromosome inhumans andmouse. TheESSScDNAfromChinesehamster cellswas clonedand shown to complement one complementation group of our previously described mutants with a proposed X-linkage. Sequence analyses of the ESSS cDNA in these mutants revealed chain termination mutations. ...

9p awards 05-04-2013 35 5   Download

HMGN1 is a nuclear protein that binds to nucleosomes and alters the accessibility of regulatory factors to their chromatin targets. To elucidate its biological function and identify specific HMGN1 target genes, we gener-ated Hmgn1–⁄– mice. DNA microarray analysis of Hmgn1+⁄+ and Hmgn1–⁄– embryonic fibroblasts identified N-cadherin as a potential HMGN1 gene target.

11p dell39 27-03-2013 34 3   Download

The peptides of the neuropeptide Y (NPY) family exert their functions, including regulation of appetite and circadian rhythm, by binding to G-protein coupled receptors. Mammals have five subtypes, named Y1,Y2 , Y4,Y5 and Y6, and recently Y7 has been discovered in fish and amphibi-ans. In chicken we have previously characterized the first four subtypes and here we describe Y6 and Y7.

16p inspiron33 26-03-2013 34 4   Download

Because arsenic is the most prevalent environmental toxin, it is imperative that we understand the mechanisms of metalloid detoxification. In prokary-otes, arsenic detoxification is accomplished by chromosomal and plasmid-borne operon-encoded efflux systems.

7p galaxyss3 21-03-2013 41 2   Download

Chromosomal rearrangements apparently account for the presence of a pri-mate-specific gene (protease serine 3) in chromosome 9. This gene encodes, as the result of alternative splicing, both mesotrypsinogen and trypsino-gen 4. Whereas mesotrypsinogen is known to be a pancreatic protease, neither the chemical nature nor biological function of trypsinogen 4 has been explored previously.

11p galaxyss3 21-03-2013 40 3   Download

The function of microRNAs (miRNAs) is translational repression or mRNA cleavage of target genes by binding to 3¢-UTRs of target mRNA. In this study, we investigated the functions and the target genes of micro-RNA124a (miR124a), and imaged the miR124a-mediated repression of chromosome 14 open reading frame24(c14orf24, unknown function) during neurogenesis, using noninvasive luciferase systems.

12p vinaphone15 25-02-2013 29 2   Download

Humanb-defensin-2 (HBD-2) is an antimicrobial peptide produced by the epithelial cells that plays an important role in innate and adaptive immu-nity. Here we report that high mobility group protein N2 (HMGN2), a member of the high mobility group superfamily that affects chromatin function, modulates the expression of HBD-2 in A549 cells treated by lipo-polysaccharide.

15p cosis54 05-01-2013 48 4   Download

Chromatin is by its very nature a repressive environment which restricts the recruitment of transcription factors and acts as a barrier to polymerases. Therefore the complex process of gene activation must operate at two levels. In the first instance, localized chromatin decondensation and nucleosome displacement is required to make DNA accessible.

29p cosis54 05-01-2013 48 5   Download

While most autosomal dominant inherited cancer syndromes are due to mutations in tumor-suppressor genes (Table 79-1), there are a few interesting exceptions. Multiple endocrine neoplasia type II, a dominant disorder characterized by pituitary adenomas, medullary carcinoma of the thyroid, and (in some pedigrees) pheochromocytoma, is due to gain-of-function mutations in the protooncogene RET on chromosome 10. Similarly, gain-of-function mutations in the tyrosine kinase domain of the MET oncogene lead to hereditary papillary renal carcinoma.

5p konheokonmummim 03-12-2010 113 7   Download

Some limited understanding of self-renewal exists and, intriguingly, implicates gene products that are associated with the chromatin state, a high-order organization of chromosomal DNA that influences transcription. These include members of the polycomb family, a group of zinc finger–containing transcriptional regulators that interact with the chromatin structure, contributing to the accessibility of groups of genes for transcription.

6p konheokonmummim 03-12-2010 83 6   Download

Unequal Crossing-Over Normally, DNA recombination in germ cells occurs with remarkable fidelity to maintain the precise junction sites for the exchanged DNA sequences (Fig. 62-3). However, mispairing of homologous sequences leads to unequal crossover, with gene duplication on one of the chromosomes and gene deletion on the other chromosome. A significant fraction of growth hormone (GH) gene deletions, for example, involve unequal crossing-over (Chap. 333).

5p konheokonmummim 03-12-2010 61 3   Download