Identification of Inverted Formin 1 (FHDC1)-Interacting Proteins by BioID Proximity-Dependent Labeling.

The actin and microtubule cytoskeleton play critical roles in Golgi and cilia assembly. Inverted-Formin 1 (INF1) is a novel, microtubule-associated protein that regulates both actin and microtubule dynamics and affects Golgi and cilia assembly. A non-biased discovery based approach was used to investigate the interactome of INF1 using BioID in combination with stable isotopic labeling in cell culture (SILAC). A number of INF1-interacting proteins were identified and validated in co-IP experiments. The INF1 interaction domains were mapped using an extensive set of INF1 deletion and point mutation derivatives. Functional characterization of these interactions suggests a mechanism for the effects of INF1 on ciliogenesis. \ud The establishment and maintenance of cellular architecture requires the coordinated, dynamic regulation of actin and microtubule networks. Our data suggests that INF1 plays a crucial role in connecting these two cytoskeletal networks for the regulated assembly of the Golgi ribbon and the primary cilium