Project description:p130Cas (Cas, Crk-associated substrate) is an adaptor molecule composed of an N-terminal Src homology 3 (SH3) domain, a substrate domain (SD), and a C-terminal Src binding domain (SBD). The SH3 domain of Cas has been shown to associate with various signaling molecules, including focal adhesion kinase (FAK), but its role in cellular function remains unclear. To address this issue, we established and analyzed primary fibroblasts derived from mice expressing a truncated Cas lacking the exon 2 encoding the SH3 domain (Cas exon 2∆/∆). In comparison to wild-type (Cas exon 2+/+) cells, Cas exon 2∆/∆ primary fibroblasts showed delayed migration in wound healing and reduced spreading on fibronectin (FN), which would be due to reduced complex formation of Cas exon 2∆/∆ with FAK and CrkII and also to impaired localization of Cas exon 2∆/∆ to focal adhesions on FN. In addition, to analyze downstream signaling pathway regulated by Cas exon 2, we compared gene expression profiles between Cas exon 2+/+ and Cas exon 2∆/∆ cells by a microarray analysis. Interestingly, we found that Cas exon 2-deficiency upregulated expression of CXC Chemokine Receptor-4 (CXCR4), CC Chemokine Receptor-5 (CCR5), and thrombospondin 4, which are implicated in cell motility and adhesion. These results define the role of Cas SH3-encoding exon in cell motility, FAK/Cas/CrkII complex formation, recruitment of Cas to focal adhesions, and regulation of cell adhesion-associated gene expression in primary fibroblasts. Keywords: SH3-encoding exon, p130Cas
Project description:CRISPR-Cas immune systems function to defend prokaryotes against potentially harmful mobile genetic elements including viruses and plasmids. The multiple CRISPR-Cas systems (Types I, II, III) each recognize and target destruction of foreign invader nucleic acids via structurally and functionally diverse effector complexes (crRNPs). CRISPR-Cas effector complexes are comprised of CRISPR RNAs (crRNAs) that contain sequences homologous to the invading nucleic acids and Cas proteins specific to each immune system type. We have previously characterized a crRNP in Pyrococcus furiosus (Pfu) that contains Cmr proteins (Type III-B) associated with one of two primary size forms of crRNAs and functions through homology-dependent cleavage of target RNAs. In the current study, we have isolated and characterized two additional native Pfu CRISPR-Cas complexes containing either Csa (Type I-A) or Cst (Type I-G) proteins and distinct profiles of associated crRNAs. For each complex, the Cas proteins were identified by tandem mass spectrometry and immunoblotting and the crRNAs by RNA deep sequencing and Northern blot analysis. The crRNAs associated with both the Csa and Cst complexes originate from each of seven total CRISPR loci and contain identical 5’ ends (8-nt CRISPR RNA repeat-derived 5’ tag sequences) but heterogeneous 3’ ends (containing variable amounts of downstream repeat sequences). These crRNA forms are distinct from Cmr-associated crRNAs, indicating different 3’ end processing pathways following primary cleavage of common pre-crRNAs. We predict that the newly identified Pfu Type I-A (Csa) and Type I-G (Cst)-containing crRNPs, like other previously characterized Type I CRISPR-Cas effector complexes, each function by carrying out crRNA-guided DNA targeting of invading mobile genetic elements. Taken together, our in-depth characterization of the three isolated native complexes provides clear evidence for three compositionally distinct crRNPs containing either Cmr, Csa, or Cst Cas proteins that together make up an impressive arsenal of CRISPR-Cas defense for a single organism. 4 Samples: Protein-associated small RNAs
Project description:p130Cas (Cas, Crk-associated substrate) is an adaptor molecule composed of an N-terminal Src homology 3 (SH3) domain, a substrate domain (SD), and a C-terminal Src binding domain (SBD). The SH3 domain of Cas has been shown to associate with various signaling molecules, including focal adhesion kinase (FAK), but its role in cellular function remains unclear. To address this issue, we established and analyzed primary fibroblasts derived from mice expressing a truncated Cas lacking the exon 2 encoding the SH3 domain (Cas exon 2â/â). In comparison to wild-type (Cas exon 2+/+) cells, Cas exon 2â/â primary fibroblasts showed delayed migration in wound healing and reduced spreading on fibronectin (FN), which would be due to reduced complex formation of Cas exon 2â/â with FAK and CrkII and also to impaired localization of Cas exon 2â/â to focal adhesions on FN. In addition, to analyze downstream signaling pathway regulated by Cas exon 2, we compared gene expression profiles between Cas exon 2+/+ and Cas exon 2â/â cells by a microarray analysis. Interestingly, we found that Cas exon 2-deficiency upregulated expression of CXC Chemokine Receptor-4 (CXCR4), CC Chemokine Receptor-5 (CCR5), and thrombospondin 4, which are implicated in cell motility and adhesion. These results define the role of Cas SH3-encoding exon in cell motility, FAK/Cas/CrkII complex formation, recruitment of Cas to focal adhesions, and regulation of cell adhesion-associated gene expression in primary fibroblasts. Experiment Overall Design: RNA samples extracted from Cas exon 2+/+, Cas exon 2+/â, and Cas exon 2â/â fibroblasts (12.5dpc, two embryos for each genotype) were labeled and hybridized on Affymetrix microarray. Gene expression patterns of Cas exon 2â/â fibroblasts were compared with those of Cas exon 2+/+ and Cas exon 2+/â cells.
Project description:The CRISPR-Cas universe continues to expand. The type II CRISPR-Cas system from Streptococcus pyogenes (SpyCas9) is most widely used for genome editing due to its high efficiency in cells and organisms. However, concentrating on a single CRISPR-Cas system imposes limits on target selection and multiplexed genome engineering. We hypothesized that CRISPR-Cas systems originating from different bacterial species could operate simultaneously and independently due to their distinct single-guide RNAs (sgRNAs) or CRISPR-RNAs (crRNAs), and protospacer adjacent motifs (PAMs). Additionally, we hypothesized that CRISPR-Cas activity in zebrafish could be regulated through the expression of inhibitory anti-CRISPR (Acr) proteins. Here, we use a simple mutagenesis approach to demonstrate that CRISPR-Cas systems from Streptococcus pyogenes (SpyCas9), Streptococcus aureus (SauCas9), Lachnospiraceae bacterium (LbaCas12a, previously known as LbCpf1), Acidaminococcus sp. (AspCas12a, previously known as AsCpf1) and Neisseria meningitidis (Nme2Cas9) are orthogonal systems capable of operating simultaneously in zebrafish. We implemented multichannel CRISPR recording using up to three CRISPR systems, and show that LbaCas12a may provide superior information density compared to previous methods. We also demonstrate that type II Acrs (anti-CRISPRs) are effective inhibitors of SpyCas9 in zebrafish. These results indicate that at least five CRISPR-Cas systems and two anti-CRISPR proteins are functional in zebrafish embryos. These orthogonal CRISPR-Cas systems and Acr proteins will enable combinatorial and intersectional strategies for spatiotemporal control of genome editing and genetic recording in animals.
Project description:Staphylococcus aureus is a gram-positive cocci and an important human commensal bacteria and pathogen. S. aureus infections are increasingly difficult to treat because of the emergence of highly resistant MRSA (Methicillin-resistant S. aureus) strains. Here we present a method to study differential gene expression in S. aureus using high-throughput RNA-sequencing (RNA-seq). We use RNA-seq to examine the differential gene expression in S. aureus RN4220 cells containing an exogenously expressed transcription factor and between two S. aureus strains (RN4220 and NCTC8325-4). The information provided by RNA-seq was a significant advance over previously described microarray based techniques. We investigated the sequence and gene expression differences between RN4220 and NCTC8325-4 and used the RNA-seq data to identify S. aureus promoters suitable for in vitro analysis. We used RNA-seq to describe, on a genome wide scale, genes positively and negatively regulated by a phage encoded transcription factor, gp67. RNA-seq offers the ability to study differential gene expression with single-nucleotide resolution, and is a considerable improvement over the predominant genome-wide transcriptome technologies used in S. aureus. RNA-seq analysis of Staphylococcus aureus RN4220 (electrocompetent strain) carrying either empty pRMC2 (inducible expression vector) or pRMC2 carrying the ORF67 gene (encodes gp67). Both strains were grown to OD 0.2 and transgene expression was induced with 100ng/ml anhydrotetracycline. As a control, Staphylococcus aureus strain NCTC8325-4 (non-electrocompetent strain) was grown under identical conditions except without the addition of anhydrotetracycline.