The role of ubiquitination to determine Non-Smad signaling responses

Abstract

Ubiquitination is a posttranslational modifi cation of proteins which acts as a key regulator of their function as well as fate. We have recently reported transforming growth factor β (TGFβ)-induced activation of non- Smad signaling responses through a specifi c Lys63-linked polyubiquitination of TGFβ type I receptor and TGFβ-associated kinase 1 (TAK1) that are utilized to specify cellular responses in cancer cells. This chapter gives a brief introduction of the biological importance of ubiquitination of proteins, the methods we have used for detecting new partners in the TGFβ signaling pathway and for performing ubiquitination assays.