The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We have purified two distinct DNA methyltransferases from pea shoot tips and analysed their sequence specificity using synthetic oligodeoxyribonucleotide substrates and chemical sequencing methods. One methylates only CG target sequences, whereas the other methylates only CAG or CTG target sequences. We have found no evidence for methylation of the 5 cytosine in CCG target sequences either in...
A replacement vector convenient for introducing subtle mutations into various mouse genes has been developed using, as a model system, the mouse transthyretin-encoding gene (ttr) and mouse embryonal carcinoma F9 cells. The vector consists of part of ttr carrying a subtle mutation in its second exon, and a cassette of the neomycin-resistance (neo)- and herpes simplex virus thymidine kinase (HSV-tk)-encoding...
Genes encoding the type I restriction-modification (R-M) system of the bovine pathogen, Pasteurella haemolytica, have been identified immediately downstream of a locus that encodes a transcriptional activator of P. haemolytica leukotoxin expression. Type I enzymes are encoded by three genes called hsdM, hsdS and hsdR, and have fallen into three groups, called Ia, Ib and Ic. HsdS provides a sequence...
Nucleotide sequences similar to del1 retrotransposon from Lilium henryi have been discovered in Zea diploperennis as a consequence of finding a Zea retrotransposon element inserted into one of them. These sequences named Zdel (Zea del1-like) elements are present in all the Zea species (about 100 copies per haploid genome) and in Tripsacum dactyloides and absent from closely related genera. Sequences...
The problem of host cell nonpermissiveness to retrovirus infection is characterized and illustrated on several retroviral models, including the role of viral receptors, cell fusion, and endogenous retroviral genomes as modifiers of the outcome of retroviral infection. Special attention is paid to different barriers against the infection of mammalian cells with avian leukosis/sarcoma viruses (ALV/ASV)...
The mouse ribosomal protein S3a-encoding gene (mRPS3a) was cloned and sequenced in this study. mRPS3a shares identical exon/intron structure with its human counterpart. Both genes are split to six exons and exhibit remarkable conservation of the promoter region (68.8% identity in the 250bp upstream of cap site) and coding region (the proteins differ in two amino acids). mRPS3a displays many features...
Necdin is a growth suppressor expressed in virtually all postmitotic neurons in the brain. The human necdin gene, NDN, is maternally imprinted and deleted in the Prader–Willi syndrome, a neurobehavioral contiguous gene disorder. Here, we isolated and characterized the human chromosomal necdin gene and its promoter region. The necdin gene is intronless, and it encodes a protein of 321 amino acid residues,...
The class-IIS restriction endonuclease, R.MmeI, was isolated from Methylophilus methylotrophus. It was originally described as a monomeric enzyme, with the native M r 105 000±7000, which did not cleave DNA efficiently [Boyd et al. (1986) Nucleic Acids Res. 14, 5255–5274; Tucholski et al. (1995) Gene 157, 87–92]. However, it was discovered that R.MmeI endonucleolytic activity is enhanced by...
DNA is organized into a hierarchy of structures, resulting in the level of compaction required to pack 2m of DNA into a nucleus with a diameter of 10μm. The orderly packaging of DNA in the nucleus plays an important role in the functional aspects of gene regulation. A small percentage of chromatin is made available to transcription factors and the transcription machinery, while the remainder of the...
Retroviruses are known to integrate in the host cell genome as proviruses, and therefore they are prone to cell-mediated control at the transcriptional and posttranscriptional levels. This plays an important role especially after retrovirus heterotransmission to foreign species, but also to differentiated cells. In addition to host cell-mediated blocks in provirus expression, also so far undefined...
Genes encoding linker histone variants have evolved to link their expression to signals controlling the proliferative capacities of cells, i.e. cycling and growth-arrested cells express distinct and specific H1 subtypes. In metazoan, these variants show a tripartite structure, with considerably divergent sequences in their amino and carboxyl terminus domains. The aim of this review is to show how...
We identified a maternally methylated CpG island at the mouse Zac1 locus on chromosome (Chr.) 10 in a screen for imprinted genes. The homologous human gene ZAC (also known as LOT1 and PLAGLI) is a candidate gene for transient neonatal diabetes (TNDM), an imprinted disorder associated with paternal duplication for 6q24 and characterized by intrauterine growth retardation and insulin dependence. A mouse...
Small nucleolar RNAs (snoRNAs) are required for ribose 2′-O-methylation of eukaryotic ribosomal RNA. Through computer search in international rice genome database, a novel U14 snoRNA gene cluster, consisting of two U14 snoRNA gene candidates, was found on rice chromosome II. They both have box C/D sequences and a 14 nucleotides (nt)-long complementarity to rice 18S ribosomal RNA (rRNA). Functional...
Acid sensing ion channel (ASIC)2 belongs to the amiloride-sensitive Na + -channel/ degenerin family. Our previous studies suggested that differential regulation of ASIC2 expression occurs between high-grade glial-derived tumor cells and normal astrocytes. To investigate the mechanisms involved in the regulation of ASIC2 gene expression, the human ASIC2 promoter region (-1551 to +117) was cloned...
Neuroblastomas are the most frequently occurring solid tumors in children under 5 years. Spontaneous regression is more common in neuroblastomas than in any other tumor type, especially in young patients under 12 months. Unfortunately, the full clinical spectrum of neuroblastomas also includes very aggressive tumors, unresponsive to multi-modality treatment and accounting for most of the pediatric...
Histones are the building units of nucleosomes and play essential roles in DNA replication, repair and transcription. A comprehensive analysis of histone genes revealed that the Plasmodium falciparum genome encodes a canonical form of each core histone and four histone variants H2A.Z, H3.3, centromere-specific H3 (CenH3), and H2Bv. Mass spectrometry confirmed the synthesis of all histones except CenH3...
Several approaches are used to survey genomic DNA methylation patterns, including Southern blot, PCR, and microarray strategies. All of these methods are based on the use of methylation-sensitive isoschizomer restriction enzyme pairs and/or sodium bisulfite treatment of genomic DNA. They have many limitations, including PCR bias, lack of comprehensive assessment of methylated sites, labor-intensive...
SLC22A18, a poly-specific organic cation transporter, is paternally imprinted in humans and mice. It shows loss-of-heterozygosity in childhood and adult tumors, and gain-of-imprinting in hepatocarcinomas and breast cancers. Despite the importance of this gene, its transcriptional regulation has not been studied, and the promoter has not yet been characterized. We therefore set out to identify the...
The recently identified transcription factor YY2 shares important features with the well characterized YY1 zinc finger protein. Both proteins mediate activating as well as repressing transcriptional properties and bind specifically to an identical DNA consensus motif, suggesting synergistic or competitive function of both factors in controlling target genes. In fact, the human yy2 gene has evolved...
Mutations in DFNA5 cause a non-syndromic autosomal dominant type of hearing loss. Although not much is known regarding the physiological function of DFNA5, it is not only related to hearing loss. A clear link with cancer exists. For example, methylation of the 5′ flanking region of DFNA5 was detected in breast, colorectal and gastric cancer. So far, this 5′ flanking region has not been studied in...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.