Journal: Arthritis and rheumatism
Article Title: Defective DNA double-strand break repair in pediatric systemic lupus erythematosus.
doi: 10.1002/art.33334
Figure Lengend Snippet: Figure 6. Non-homologous DNA end joining (NHEJ) pathway. A, NHEJ assay. Ten micrograms of nuclear lysate from lymphoblastoid cell lines from patients with systemic lupus erythematosus (SLE) was added to 250 ng of Sma I–digested (SmaI[]) pUC19 DNA. Nuclear lysates from all SLE cell lines and a wild-type (WT) control cell line (Paris1) efficiently ligated Sma I–digested plasmid, forming higher-order multimers (upper right). Exclusion of MgCl2 (WT[]MgCl) served as a negative control (see Materials and Methods). Quantification of ligation efficiency was calculated using the dimer and a representative multimer band (asterisk). A linear form of the plasmid (Uncut pUC19) was used as the loading control. B, Immunoblot analysis of 7 core proteins involved in NHEJ. Fifty micrograms of whole cell extract isolated from each SLE lymphoblastoid cell line was used to immunoblot for DNA-dependent protein kinase, catalytic subunit (DNA-PKcs), Ku70, Ku80, Artemis, XLF/Cernunnos (XLF), DNA ligase IV (Lig 4), and XRCC4. Beta-actin or structural maintenance of chromosomes protein 1 (SMC1) was used as a loading control and is shown below the corresponding immunoblots. All 7 core proteins were present in the 16 SLE cell line extracts tested. SLE 64 and SLE 73 were retested for Ku70 and Ku80; SLE 68 was retested for XRCC4 and Lig 4. All cell lines were normal (not all data are shown).
Article Snippet: For visualizing Fanconi protein D2 monoubiquitination products or SMC1 phosphorylation, a 7.5% SDSPAGE gel was electrophoresed; the immunoblot was incubated overnight with either FANCD2 antibody or SMC1 [p Ser966] antibody (both from Novus Biologicals); secondary antibody was detected with an HRP conjugate.
Techniques: NHEJ Assay, Control, Plasmid Preparation, Negative Control, Ligation, Western Blot, Isolation