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.
Chapter 12 - The Eukaryotic chromosome. This chapter describes the structure of eukaryotic chromosomes and how that structure affects function. The very long, linear DNA molecules are compacted with proteins in the chromosomes to fit into the nucleus. Several structures are essential for duplication, segregation, and stability.
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
(H)-specific MDH, which catalysed reversible inter-conversion of malate to oxaloacetate.
Ebook Fourth edition compiled essential cell biology with content: The fundamental Uunits of Llife; Chemical components of cells; Energy, catalysis, and biosynthesis; Protein structure and function; DNA and chromosomes; DNA replication, repair, and recombination, from DNA to Protein: How cells read the genome;... To learn more about ebook invite you to consult the documentation.
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.
Idiopathic Parkinson’s disease (PD) is an age-dependent, neurodegenerative
disorder and is predominantly sporadic. Only 20–30% of patients have a positive
family history for PD with a complex mode of inheritance. In a few
extended families, the disease is inherited as an autosomal dominant trait. Linkage
to chromosome 4 was reported in a large Italian kindred multiply affected
by an early-onset form of PD (1). However, this finding was not replicated in a
sample of 94 Caucasian families by Scott et al. (2), or in 13 multigenerational
families by Gasser et al. (3)....
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.
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.
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.
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. ...
Uncovering Recurrent Submicroscopic Rearrangements As a Cause of Disease
For five decades since Fred Sanger's (1) seminal discovery that proteins have a specific
structure, since Linus Pauling's (2) discovery that hemoglobin from patients with sickle
cell anemia is molecularly distinct, and since Watson and Crick's (3) elucidation of the
chemical basis of heredity, the molecular basis of disease has been addressed in the
context of how mutations affect the structure, function, or regulation of a gene or its
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.
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.
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,
EC184.108.40.206) 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.
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 dierent 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.
Genetics is the science of genes, heredity, and the variation of organisms. Genes encode the information necessary for synthesizing proteins, which in turn play a large role in influencing (though, in many instances, not completely determining) the final phenotype of the organism. In modern research, genetics provides important tools in the investigation of the function of a particular gene, or the analysis of genetic interactions. Within organisms, genetic information generally is carried in chromosomes, where it is represented in the chemical structure of particular DNA molecules....
Telomeres, located at the ends of linear chromosomes, are essential for genome stability and integrity. Advances in telomere researches have linked telomere dysfunction with cellular aging and a number of age-related human diseases. Recent studies further expanded our knowledge of telomere functions - telomeres are shown to be important for microbial pathogen virulence and telomere proteins have important non-telomeric cellular functions.
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.
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.
RNomics is a newly emerging sub-discipline of genomics that categorically
studies the structure, function and processes of non-coding ribo nucleic acids in
a cell. MicroRNomics is a sub-field of RNomics that describes the biogenesis and
mechanisms of tiny RNA regulators, and their involvement in the processes of
development, differentiation, cell proliferation, cell death, chromosomal segregation
and metabolism. The discovery of microRNAs in species ranging from
Caenorhabditis elegans (C.