Distinguishing parallel from series circuits with a double knockdown procedure in human cell lines.

Signaling cascades can act in series or in parallel. Here, we describe a convenient and robust protocol for dual, sequential knockdown of two proteins using RNA interference. We detail the steps for a quantitative mapping of signaling circuitry. We used this approach to study kinases in human ovarian cancer cells, but the protocol can be applied to many other posttranslational modifications. For complete details on the use and execution of this protocol, please refer to Gocher et al. (2017).1.