A substitution mutation has been introduced into the c- abl locus of murine embryonic stem cells by homologous recombination between exogenously added DNA and endogenous gene, these have used to generate chimeric mice. It is shown that was transmitted progeny several male chimeras. This work demonstrates feasibility germ-line transmission a nonselectable autosomal gene recombination.

Yin-Yang-1 (YY1) regulates the transcription of many genes, including oncogenes c- fos and myc . Depending on context, YY1 acts as a transcriptional repressor, activator, or initiator. The yeast two-hybrid system was used to screen human complementary DNA (cDNA) library for proteins that associate with YY1, cDNA isolated. Affinity chromatography confirmed associates c-Myc but not Max. In cotransfections, inhibits both repressor activator functions which suggests one way is by modulating activity YY1.

Epstein-Barr nuclear antigen 2 (EBNA2), one of the six viral proteins expressed in latently infected B lymphocytes, is essential to immortalization cells by virus (EBV). EBNA2 promotes transcriptional transactivation and cellular genes acting as an adapter molecule that binds sequence-specific DNA-binding proteins, JK recombination signal-binding protein (RBP-JK), PU.1 engages multiple members RNA polymerase II transcription complex. In present study, we show also interacts with hSNF5/Ini1,...

A plasmid construct expressing the p66 version of human immunodeficiency virus reverse transcriptase as a bacterial fusion protein was subjected to in vitro mutagenesis, and resulting variant proteins were assayed define locations two major enzymatic activities. The DNA polymerase activity localized N-terminal portion protein; mutations altering or eliminating C-terminal had little no effect on that activity. results suggest that, contrast with previous reports, p51 subunit found virions...

A critical step for retroviral replication is the stable integration of provirus into genome its host. The viral integrase protein key in this essential life cycle. Although basic mechanism by mammalian retroviruses has been well characterized, factors determining how events are targeted to particular regions or a DNA structure remain poorly defined. Significant questions regarding influence host proteins on selection target sites, repair intermediates, and efficiency integration. We...

The reverse transcriptase enzymes of retroviruses are multifunctional proteins containing both DNA polymerase activity and a nuclease activity, termed RNase H, specific for RNA in RNA-DNA hybrid form. To determine the role H retroviral replication, we constructed series mutant genomes Moloney murine leukemia virus that encoded were specifically altered to retain function but lack activity. all replication defective. Analysis vitro transcription reactions carried out by virions showed...

The process of reverse transcription retroviral genomes begins with the synthesis a short DNA molecule near 5' end RNA template. This molecule, termed minus-strand strong-stop DNA, is then translocated to 3' viral by means repeated sequence, R region, present at both ends translocation should result in transfer genetic information from region region. We have generated series mutants Moloney murine leukemia virus alterations regions vitro mutagenesis cloned copy genome. altered DNAs were...

Murine leukemia viruses (MLVs) and related retroelements are potently restricted in embryonic cells by postintegration transcriptional silencing, likely to protect the germ line from insertional mutagenesis. This silencing is large part attributable presence of a nuclear repression complex, which targets sequence element proviral DNA, repressor-binding site. The site closely overlaps tRNA primer binding site, highly conserved essential for virus replication defining initiation DNA synthesis...

The c-Abl protein is a ubiquitously expressed nonreceptor tyrosine kinase involved in the development and function of many mammalian organ systems, including immune system bone. Here we show that homozygous Abl mutant embryos newborns on C57BL/6J background, but not other backgrounds, display dramatically enlarged hearts die perinatally. heart defects can be largely rescued by cardiomyocyte-specific restoration full-length protein. cardiac hyperplasia phenotype caused decreased apoptosis,...

The ataxia telangiectasia mutant (ATM) protein is an intrinsic part of the cell cycle machinery that surveys genomic integrity and responses to genotoxic insult. Individuals with as well Atm(-/-) mice are predisposed cancer infertile due spermatogenesis disruption during first meiotic prophase. spermatocytes frequently display aberrant synapsis clustered telomeres (bouquet topology). Here, we used telomere fluorescent in situ hybridization immunofluorescence (IF) staining SCP3...

The appearance of drug-resistant strains viral pathogens is a major difficulty confounding current efforts to block infections. identification and analysis mutations responsible for drug resistance can provide important clues helpful in understanding the mechanisms eventual development better therapies. We have used direct screening method scan libraries mutagenized genes encoding reverse transcriptase human immunodeficiency virus type 1, recovered variant enzyme that resistant...

Reverse transcription of retroviral genomic RNA is, in a sense, discontinuous process. The production each strand integration-competent DNA begins with the synthesis short, discrete products that can be elongated only after they are moved to secondary template locations process called transfer. Both transfers during reverse involve translocation short from their sites at one end genome acceptor regions other genome, where resumes. Because strand-transfer reactions, final product is linear...

Human immunodeficiency virus type 1 (HIV-1) continues to be a major burden human health worldwide. How infected cells recognize and respond HIV-1 infection is important in order better understand the biology of cellular pathways activated upon identify potential targets that interfere with viral replication. In this study, we investigated innate immune responses different cell types following single-cycle (replication-defective) reporter virus. We report commonly used strain (lacking env ,...

The retroviral integrase protein (IN) is responsible for catalyzing a concerted integration reaction in which the two termini of linear viral DNA are joined to host DNA. To probe potential IN form multimers, we used yeast two-hybrid system. coexpression GAL4 binding domain-IN fusion and activation together resulted successful GAL4-responsive LacZ reporter gene. system was examine variety deletion mutants. results suggest that central region necessary multimerization N-terminal zinc finger...

c-Abl is a non-receptor tyrosine kinase implicated in DNA damage-induced cell death and growth factor receptor signaling. To further understand the function regulation of c-Abl, yeast two-hybrid screen was performed to identify c-Abl-interacting proteins. Here we report identification Abl-philin 2 (Aph2), encoding novel protein with unique cysteine-rich motif (<i>zf</i>-DHHC) 53-amino acid stretch sharing homology creatine family. The<i>zf</i>-DHHC domain highly conserved from human. Two...

The capsid domain (CA) of the retroviral Gag protein is a major constituent virion core. To examine role this in M-MuLV morphogenesis and replication, series substitution mutations affecting central region CA were introduced into an infectious proviral DNA. altered DNAs cells, resulting lines analyzed for production virions. Only one replication defective mutants was blocked assembly. remaining mutant induced formation release particles containing genomic RNA polymerase protein. reverse...

Mutations in the β-subunit of cGMP-phosphodiesterase (PDE6β) can lead to either progressive retinal disease, such as human retinitis pigmentosa (RP), or stationary congenital night blindness (CSNB). Individuals with CSNB Rambusch pedigree were found carry H258N allele PDE6B (MIM# 180072); a similar mutation was not RP patients. This report describes an individual carrying allele, who presented generalized dysfunction affecting rod system and locus at rod-bipolar interface. Also described are...

Viruses often use host machinery in unusual ways to execute different steps during their replication. To identify factors critical for virus replication, we screened cDNA expression libraries genes or gene fragments that could interfere with HIV-1 vector transduction. The DNA clone most potently inhibited encoded the N-terminal 91 aa of eukaryotic initiation factor 3 subunit f (N91-eIF3f). Overexpression N91-eIF3f full-length eIF3f drastically restricted replication by reducing nuclear and...