Journal: bioRxiv
Article Title: Intrinsic RNA targeting constrains the utility of CRISPR-Cas13 systems
doi: 10.1101/2022.05.14.491940
Figure Lengend Snippet: (A) Western blot of protein extracts from HEK293FT cells transiently expressing different Cas13 effectors in one-vector format. (B) Immunocytochemistry of Cas13 proteins showing localization and expression. Scale bar, 20 µm. (C-D) Surviving cell number after puromycin selection for T47D (C) or LNCaP (D) cells infected by indicated one-vector Cas13 lentiviruses, mean ± SEM with n = 3. (E) Cell viability analysis for HEK293FT cells with transient transfection of indicated one-vector lentiviral constructs, mean ± SEM with n = 3. Vector: lentiv2-w/o Cas9. (F) Cell viability analysis for HEK293FT cells during lentivirus production by transient transfection of one-vector Cas13 along with packaging plasmids, mean ± SEM with n = 3. (G-I) Assessment of surviving cell number (G), lentiviral RNA (H) and integrated lentiviral DNA (I) in A549 cells infected with indicated lentiviruses at low MOI. (J-L) Assessment of surviving cell number (J), lentiviral RNA (K) and integrated lentiviral DNA (L) in A549 cells infected with indicated lentiviruses containing different crRNAs. (M) Evaluation of lentiviral defect for one-vector Cas13 systems under pHAGE-EF1α-puro plasmid backbone.
Article Snippet: The following plasmid backbones were used in this study: lentiCRISPR v2 (lentiv2, Addgene #52961): a lentiviral vector backbone, U6 promoter expresses Cas9 sgRNA scaffold; EF1α promoter expresses Cas9 and PuroR (puromycin resistance) with P2A linker; lentiGuide-puro (Addgene #52963): an empty lentiviral vector expresses Cas9 sgRNA under U6 promoter with puromycin resistance; lenti-Cas9-blast (Addgene #52962): a lentiviral vector expresses Cas9 protein and blasticidin resistance under EF1α promoter. pHAGE-EF1α-puro: an empty lentiviral vector backbone, EF1α promoter drives expression of inserted cDNA; SV40 promoter expresses PuroR; pcDNA3.1: a derivative of pcDNA3.1-HA (Addgene #128034) vector, without HA tag; lentiv2-w/o Cas9: a derivative of the lentiCRISPR v2 vector with Cas9 open reading frame (ORF) removal; pET-28a(+): bacterial vector for expression of N-terminally 6xHis-tagged proteins with a thrombin site.
Techniques: Western Blot, Expressing, Plasmid Preparation, Immunocytochemistry, Selection, Infection, Transfection, Construct