- Developmental Biology and Gene Regulation
- RNA Interference and Gene Delivery
- RNA Research and Splicing
- Virus-based gene therapy research
- Pluripotent Stem Cells Research
- RNA and protein synthesis mechanisms
- Cellular Mechanics and Interactions
- Neurobiology and Insect Physiology Research
- Coagulation, Bradykinin, Polyphosphates, and Angioedema
- Nuclear Receptors and Signaling
- 14-3-3 protein interactions
- CRISPR and Genetic Engineering
- Cerebrovascular and genetic disorders
- Wnt/β-catenin signaling in development and cancer
- Estrogen and related hormone effects
- Viral Infections and Immunology Research
- Genomics and Phylogenetic Studies
- Hippo pathway signaling and YAP/TAZ
- Neuroscience and Neuropharmacology Research
- Cancer Cells and Metastasis
- Bacterial Genetics and Biotechnology
- Protein Kinase Regulation and GTPase Signaling
- Herpesvirus Infections and Treatments
- Cytomegalovirus and herpesvirus research
- Invertebrate Immune Response Mechanisms
California Institute of Technology
2006-2025
Howard Hughes Medical Institute
2010-2025
City of Hope
2005-2007
City Of Hope National Medical Center
2005-2007
Stanford University
2006
Huntington Hospital
2005
University of Southern California
2005
RNAi is proving to be a powerful experimental tool for the functional annotation of mammalian genomes. The full potential this technology will realized through development approaches permitting regulated manipulation endogenous gene expression with coordinated reexpression exogenous transgenes. We describe lentiviral vector platform, pSLIK (single lentivector inducible knockdown), which permits tetracycline-regulated microRNA-like short hairpin RNAs from single viral infection any naïve cell...
The Notch signaling pathway comprises multiple ligands that are used in distinct biological contexts. In principle, different could activate target programs signal-receiving cells, but it is unclear how such ligand discrimination occur. Here, we show cells use dynamics to discriminate by the Dll1 and Dll4 through Notch1 receptor. Quantitative single-cell imaging revealed activates discrete, frequency-modulated pulses specifically upregulate gene Hes1. By contrast, a sustained,...
A system for programmable export of RNA molecules from living cells would enable both non-destructive monitoring cell dynamics and engineering capable delivering executable programs to other cells. We developed genetically encoded cellular exporters, inspired by viruses, that efficiently package secrete cargo mammalian within protective nanoparticles. Exporting sequencing barcodes enabled population with clonal resolution. Further, incorporating fusogens into the nanoparticles, we...
The Notch signaling pathway consists of transmembrane ligands and receptors that can interact both within the same cell (cis) across boundaries (trans). Previous work has shown cis-interactions act to inhibit productive signaling. Here, by analyzing activation in single cells while controlling density ligand expression level, we show cis-ligands also activate receptors. This cis-activation process resembles trans-activation its level dependence, susceptibility cis-inhibition, sensitivity...
Developing tissues form spatial patterns by establishing concentration gradients of diffusible signaling proteins called morphogens. The bone morphogenetic protein (BMP) morphogen pathway uses a family extracellular modulators to reshape actively “shuttling” ligands different locations. It has remained unclear what circuits are sufficient enable shuttling, other they can generate, and whether shuttling is evolutionarily conserved. Here, using synthetic, bottom-up approach, we compared the...
Effective and stable knockdown of multiple gene targets by RNA interference is often necessary to overcome isoform redundancy, but it remains a technical challenge when working with intractable cell systems.We have developed flexible platform using polymerase II promoter-driven expression microRNA-like short hairpin RNAs which permits robust depletion target genes from single transcript. Recombination-based subcloning multi-shRNA transcripts comprehensive range plasmid or viral vectors....
The Notch signaling pathway uses families of ligands and receptors to transmit signals nearby cells. These components are expressed in diverse combinations different cell types, interact a many-to-many fashion, both within the same (in cis) between cells trans), their interactions modulated by Fringe glycosyltransferases. A fundamental question is how strength depends on which expressed, at what levels, Here, we used quantitative, bottom-up, cell-based approach systematically characterize...
A recombinant AAV2 (rAAV2) vector encoding antisense RNA to HIV-1 transactivating region (TAR) was evaluated for transduction of human cord blood CD34 + CD38 - hematopoietic stem cells (HSC) capable serial engraftment in nonobese diabetic (NOD)/severe combined immunodeficient (SCID) mice. Results revealed long-term multilineage marking primary and secondary recipients, significantly, an enrichment transduced hosts, indicating efficient multipotential self-renewing HSC. These results were...
We have previously demonstrated recombinant adeno-associated viral (rAAV) transduction of human CD34(+) hematopoietic stem cells (HSCs) capable serial engraftment in vivo. Here we evaluated the capacity rAAV2 to mediate gene transfer into nondividing, quiescent, primitive subdivided on basis metabolic, mitotic, and phenotypic properties. Results revealed that CD34(+)CD38() marrow are most exist primarily G(0) at isolation only population remain nondividing during entire exposure free rAAV....
Cellular responses to inputs that vary both temporally and spatially are determined by complex relationships between the components of cell signaling networks. Analysis these requires access a wide range experimental reagents techniques, including ability express protein model cells in variety contexts. As part Alliance for Signaling, we developed robust method cloning large numbers ORFs into Gateway® entry vectors, created compatible expression platforms proteomics applications. To date,...
Abstract The Notch signaling pathway uses families of ligands and receptors to transmit signals nearby cells. These components are expressed in diverse combinations different cell types, interact a many-to-many fashion, both within the same (in cis) between cells trans), their interactions modulated by Fringe glycosyltransferases. A fundamental question is how strength depends on which expressed, at what levels, Here, we used quantitative, bottom-up, cell-based approach systematically...
The use of RNA interference to knock down protein phosphatases has proven be a valuable approach understanding the functions these enzymes in mammalian cells. Many exist as multisubunit and multigene families, which made it difficult assess their physiological using traditional approaches. ability selectively specific subunits individual isoforms with begun make possible determine contributions phosphatase proteins cellular signaling. This chapter describes methods for knocking small...
RNA interference (RNAi) was investigated with the aim of achieving gene silencing diverse RNAi platforms that include small interfering (siRNA), short hairpin (shRNA) and antisense oligonucleotides (ASO). Different versions each system were used to silence expression specific subunits heterotrimeric signal transducing G-proteins, G alpha i2 beta 2, in RAW 264.7 murine macrophage cell line. The specificity different assessed by DNA microarray analysis. Reliable methodologies against genes...
Abstract The Notch signaling pathway consists of transmembrane ligands and receptors that can interact both within the same cell ( cis ) across boundaries trans ). Previous work has shown -interactions act to inhibit productive signaling. Here, by analyzing activation in single cells while controlling density ligand expression level, we show -ligands fact activate receptors. This -activation process resembles its level dependence, susceptibility -inhibition, sensitivity Fringe modification....
The Notch signaling pathway uses families of ligands and receptors to transmit signals nearby cells. These components are expressed in diverse combinations different cell types, interact a many-to-many fashion, both within the same (in cis) between cells trans), their interactions modulated by Fringe glycosyltransferases. A fundamental question is how strength depends on which expressed, at what levels, Here, we used quantitative, bottom-up, cell-based approach systematically characterize...
The Notch signaling pathway uses families of ligands and receptors to transmit signals nearby cells. These components are expressed in diverse combinations different cell types, interact a many-to-many fashion, both within the same (in cis) between cells trans), their interactions modulated by Fringe glycosyltransferases. A fundamental question is how strength depends on which expressed, at what levels, Here, we used quantitative, bottom-up, cell-based approach systematically characterize...
The Notch signaling pathway uses families of ligands and receptors to transmit signals nearby cells. These components are expressed in diverse combinations different cell types, interact a many-to-many fashion, both within the same (in cis) between cells trans), their interactions modulated by Fringe glycosyltransferases. A fundamental question is how strength depends on which expressed, at what levels, Here, we used quantitative, bottom-up, cell-based approach systematically characterize...