Re-examination of siRNA specificity questions role of PICH and Tao1 in the spindle checkpoint and identifies Mad2 as a sensitive target for small RNAs.

ABSTRACT: The DNA-dependent adenosine triphosphatase (ATPase) Plk1-interacting checkpoint helicase (PICH) has recently been implicated in spindle checkpoint (SAC) signaling (Baumann et al., Cell 128(1):101-114, 2007). Depletion of PICH by siRNA abolished the SAC and resulted in an apparently selective loss of Mad2 from kinetochores, suggesting a role for PICH in the regulation of the Mad1-Mad2 interaction. An apparent rescue of SAC functionality by overexpression of PICH in PICH-depleted cells initially seemed to confirm a role for PICH in the SAC. However, we have subsequently discovered that all PICH-directed siRNA oligonucleotides that abolish the SAC also reduce Mad2 mRNA and protein expression. This reduction is functionally significant, as PICH siRNA does not abolish SAC activity in a cell lin

SUBMITTER: Hubner NC 

PROVIDER: S-EPMC2846388 | biostudies-literature | 2010 Apr

REPOSITORIES: biostudies-literature