Identification of proteins interacting with lncRNA Braveheart in mouse using protein microarray
ABSTRACT: The mouse lncRNA Braveheart (Bvht) as a non-coding transcript has been found to act in trans to regulate cardiovascular lineage commitment. However, the mechanism of Bvht action is still not clear. lncRNAs have been shown to regulate gene expression though cooperating with protein partners. Recently, we experimentally determine the secondary structure of Bvht containing a novel structural motif AGIL. AGIL motif deletion (BvhtdAGIL) in mouse embryonic stem cells prevents the transition from mesoderm cells to cardiac progenitors. To identify proteins that interact with the Bvht AGIL motif, we used a human protein microarray platform (Human ProtoArray, Life Technology). Full-length Bvht and BvhtdAGIL transcripts were generated by in vitro transcription and labeled with Cy5. 50pmol Cy5-labeled RNAs were individually incubated with the protein microarray.
Project description:The mouse lncRNA Braveheart (Bvht) as a non-coding transcript has been found to act in trans to regulate cardiovascular lineage commitment. However, the mechanism of Bvht action is still not clear. lncRNAs have been shown to regulate gene expression though cooperating with protein partners. Recently, we experimentally determine the secondary structure of Bvht containing a novel structural motif AGIL. AGIL motif deletion (BvhtdAGIL) in mouse embryonic stem cells prevents the transition from mesoderm cells to cardiac progenitors. To identify proteins that interact with the Bvht AGIL motif, we used a human protein microarray platform (Human ProtoArray, Life Technology). Full-length Bvht and BvhtdAGIL transcripts were generated by in vitro transcription and labeled with Cy5. 50pmol Cy5-labeled RNAs were individually incubated with the protein microarray.
Project description:We have developed an algorithm (âLeverâ) that systematically maps metazoan DNA regulatory motifs or motif combinations to the sets of genes that they likely regulate. Lever accomplishes this by assessing whether the motifs are enriched within cis regulatory modules (CRMs), predicted by our âPhylCRMâ algorithm, in the noncoding sequences surrounding genes in a collection of gene sets. When these gene sets correspond to Gene Ontology (GO) categories, the results of Lever analysis allow the unbiased assignment of functional annotations to the regulatory motifs and also to the candidate CRMs that comprise the genomic motif occurrences. We demonstrate these methods using human myogenic differentiation as a model system, for which we statistically assessed greater than 25,000 pairings of gene sets and motifs / motif combinations. These results allowed us to assign functional annotations to candidate regulatory motifs predicted previously, and to identify gene sets that are likely to be co-regulated via shared regulatory motifs. Lever allows moving beyond the identification of putative regulatory motifs in mammalian genomes, towards understanding their biological roles. This approach is general and can be applied readily to any cell type, gene expression pattern, or organism of interest. Keywords: expression profiling, time course Primary human skeletal muscle cells were grown in proliferating medium (DMEM + 10% FCS) for 48 hours until about 80% confluence. Cells were then switched to differentiation medium (DMEM/F12 + 2% horse serum) for 48 hours. Total RNA was extracted from cells at -48, -24, 0, +12, +24, and +48 hours relative to induction of differentiation, and labeled with either Cy5 or Cy3. Universal total RNA was also labeled with either Cy3 or Cy5 and was hybridized to the array with the experimental sample. Dye-swaps were performed in addition to duplicate hybridizations for a total of 4 hybridizations per timepoint.
Project description:Transcriptional profile of Streptococcus pyogenes stk mutant strain JRS2516 vs its wild type parent strain MGAS2221 The RNA prepared from triplicate cultures for the wild type and the stk mutant strains was each labeled with Cy3 and hybridized to duplicate arrays. Reference RNA consisted of pooled RNA for the wild type and stk mutant, labeled with Cy5.
Project description:Microarray-based experiments revealed that thyroid hormone triiodothyronine (T3) enhanced the binding of Cy5-labeled ATP on heat shock protein 90 (Hsp90). By molecular docking experiments with T3 on Hsp90, we identified a T3 binding site (TBS) near the ATP binding site on Hsp90. A synthetic peptide encoding HHHHHHRIKEIVKKHSQFIGYPITLFVEKE derived from the TBS on Hsp90 showed, in MST experiments, the binding of T3 at an EC<sub>50</sub> of 50 μM. The binding motif can influence the activity of Hsp90 by hindering ATP accessibility or the release of ADP.
Project description:Using this approach the dasatinib-oligonucleotide conjugates was applied to planar arrays of >9,000 human proteins spotted in two technical replicates. All proteins in the commercially available ProtoArray® Human Protein MicroArray (Thermo Fisher Scientific) have been purified and arrayed under native conditions to allow such studies. We adopted this format for investigation of the binding profiles of the drug-oligonucleotide conjugates. Fluorophore-labeled drugs have previously been used to measure binding in protein arrays. The oligonucleotide-conjugated constructed allowed for locally amplified detection via RCA. Circularizing oligonucleotides (padlock probes) were designed with 5’ and 3’ ends complementary to adjacent segments of the oligonucleotides conjugated to the drug molecules. Once converted to oligonucleotide circles by ligation, the probes were replicated through localized RCA, primed by the drug-conjugated oligonucleotides, and visualized using fluorescence-labeled hybridization probes to the repeated sequence of the RCA products. RCA offers a signal enhancement of several hundredfold over singly fluorophore labeled compounds, permitting visualization of even single bound drug probes
Project description:Despite significant advances on fluorescent labeling of target proteins to study their structural dynamics and function, there has been need for labeling with high quantum yield ensuring high sensitivity and selectivity without sacrificing the biological function of the protein. Here as a technical advancement over non-canonical amino acid incorporation, we provided a conceptual design of the N-terminal fluorescent tagging of proteins. Cy5-labeled methionine (Cy5-Met) was chemically synthesized, and then the purified Cy5-Met was coupled with synthetic human initiator tRNA by methionine tRNA synthetase. Cy5-Met-initiator tRNA (Cy5-Met-tRNAi) was purified and transfected into HeLa cells with HIV-Tat plasmid, resulting in an efficient production of Cy5-labeled HIV-Tat protein. Based on the universal requirement in translational initiation, the approach provides co-translational incorporation of N-terminal probe to a repertoire of proteins in the eukaryote system. This methodology has potential utility in the single molecule analysis of human proteins in vitro and in vivo for addressing to their complex biological structural and functional dynamics.
Project description:We performed two different pools for the 10 AAA patients (n=5 AAA patients in pool A and n=5 AAA patients in pool B) and two different pools for the 10 healthy subjects (n=5 controls in pool C and n=5 controls in pool D). Two replicates of the two microarray experiments were made. Experiment 1: AAA pool A Cy3 labeled vs control pool C Cy5 labeled AAA pool A Cy5 labeled vs control pool C Cy3 labeled (dye swap); Experiment 2: AAA pool B Cy3 labeled vs control pool D Cy5 labeled AAA pool B Cy5 labeled vs control pool D Cy3 labeled (dye swap).
Project description:Single-molecule fluorescence microscopy is a powerful tool for observing biomolecular interactions with high spatial and temporal resolution. Detecting fluorescent signals from individual labeled proteins above high levels of background fluorescence remains challenging, however. For this reason, the concentrations of labeled proteins in in vitro assays are often kept low compared to their in vivo concentrations. Here, we present a new fluorescence imaging technique by which single fluorescent molecules can be observed in real time at high, physiologically relevant concentrations. The technique requires a protein and its macromolecular substrate to be labeled each with a different fluorophore. Making use of short-distance energy-transfer mechanisms, only the fluorescence from those proteins that bind to their substrate is activated. This approach is demonstrated by labeling a DNA substrate with an intercalating stain, exciting the stain, and using energy transfer from the stain to activate the fluorescence of only those labeled DNA-binding proteins bound to the DNA. Such an experimental design allowed us to observe the sequence-independent interaction of Cy5-labeled interferon-inducible protein 16 with DNA and the sliding via one-dimensional diffusion of Cy5-labeled adenovirus protease on DNA in the presence of a background of hundreds of nanomolar Cy5 fluorophore.
Project description:In vitro transcribed messenger ribonucleic acid (mRNA) constitutes an emerging therapeutic class with several clinical applications. This study presents a systematic comparison of different technologies-intradermal injection, microneedle injection, jet injection, and fractional laser ablation-for the topical cutaneous delivery of mRNA. Delivery of Cy5 labeled mRNA and non-labeled enhanced green fluorescent protein (eGFP) expressing mRNA was investigated in a viable ex vivo porcine skin model and monitored for 48 h. Forty 10 µm-thick horizontal sections were prepared from each skin sample and Cy5 labeled mRNA or eGFP expression visualized as a function of depth by confocal laser scanning microscopy and immunohistochemistry. A pixel-based method was used to create a semi-quantitative biodistribution profile. Different spatial distributions of Cy5 labeled mRNA and eGFP expression were observed, depending on the delivery modality; localization of eGFP expression pointed to the cells responsible. Delivery efficiencies and knowledge of delivery sites can facilitate development of efficient, targeted mRNA-based therapeutics.
Project description:Binding of in vitro synthesized HAC1 mRNA was studied using protein microarray. 3 replicates, plus 3 reverse dye replicates An all pairs experiment design type is where all labeled extracts are compared to every other labeled extract. is_reverse: no: HAC1 mRNA Cy5 labeled; yes: HAC1 mRNA Cy3 labeled all_pairs