Figure 1. A carboxyl methyltransferase targets PCNA in human cells.
(A) MDA-MB-468 breast cancer cell extracts possess SAM-dependent carboxyl methyltransferase activities. Mean counts from vapor diffusion assays are presented ± SD and compared using student’s t-test. (B) PCNA (2, 5, or 10 μg) or bovine serum albumin (BSA) were added to breast cancer cell extracts and mean counts from vapor diffusion assay presented ± SD and results compared using student’s t-test. (C) PCNA-dependent methyltransferase activity was enriched and resolved by 2D-PAGE. The position of the C6orf211 gene product in the gel is noted with an arrow. (D) Proteins identified by LC-MS/MS in activity enriched fractions classified by cellular functions. See also Figure S1.
