RESUMO
OBJECTIVE: Chromovert® Technology is presented as a new cell engineering technology to detect and purify living cells based on gene expression. METHODS: The technology utilizes fluorogenic oligonucleotide signaling probes and flow cytometry to detect and isolate individual living cells expressing one or more transfected or endogenously-expressed genes. RESULTS: Results for production of cell lines expressing a diversity of ion channel and membrane proteins are presented, including heteromultimeric epithelial sodium channel (αßγ-ENaC), sodium voltage-gated ion channel 1.7 (NaV1.7-αß1ß2), four unique γ-aminobutyric acid A (GABAA) receptor ion channel subunit combinations α1ß3γ2s, α2ß3γ2s, α3ß3γ2s and α5ß3γ2s, cystic fibrosis conductance regulator (CFTR), CFTR-Δ508 and two G-protein coupled receptors (GPCRs) without reliance on leader sequences and/or chaperones. In addition, three novel plasmid-encoded sequences used to introduce 3' untranslated RNA sequence tags in mRNA expression products and differentially-detectable fluorogenic probes directed to each are described. The tags and corresponding fluorogenic signaling probes streamline the process by enabling the multiplexed detection and isolation of cells expressing one or more genes without the need for gene-specific probes. CONCLUSIONS: Chromovert technology is provided as a research tool for use to enrich and isolate cells engineered to express one or more desired genes.
Assuntos
Engenharia Celular/métodos , Citometria de Fluxo/métodos , Sondas de Oligonucleotídeos , Animais , Linhagem Celular , Fluorescência , Engenharia Genética , Humanos , Canais Iônicos/genética , Canais Iônicos/metabolismo , Conformação de Ácido Nucleico , Hibridização de Ácido Nucleico , Sondas de Oligonucleotídeos/química , Sondas de Oligonucleotídeos/genética , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismoRESUMO
The 12/23 rule is a critical step for regulation of V(D)J recombination. To date, only the RAG proteins and high mobility group protein 1 or 2 have been implicated in 12/23 regulation. Through protein fractionation and biochemical experiments, we find that Ku70/Ku80 and DNA-dependent protein kinase catalytic subunit (DNA-PKcs) modulate RAG-mediated cleavage. Modulation of cleavage by Ku70/80 and DNA-PKcs results in preferential inhibition of 12/12 and 23/23 DNA cleavage, thus increasing 12/23 rule specificity. This observation indicates that DNA repair factors, Ku70/80 and DNA-PKcs, might be present upstream of the DNA cleavage events and not recruited downstream as is currently thought, assigning new nonrepair functions to the DNA-dependent protein kinase.