Zinc finger FYVE domain-containing protein 9 or SARA (SMAD anchor for receptor activation) is a protein that in humans is encoded by the ZFYVE9gene. SARA contains a double zinc finger (FYVE domain).
SARA is an anchoring protein involved in TGF beta signaling. It binds to the MH2 domain of the R-SMADsSMAD2 and SMAD3 as well as the type I TGF beta receptors. It facilitates the phosphorylation of the R-SMAD, which subsequently dissociates form SARA and the receptor and binds a coSMAD where they enter the nucleus as transcription factors.
^Tsukazaki T, Chiang TA, Davison AF, Attisano L, Wrana JL (December 1998). "SARA, a FYVE domain protein that recruits Smad2 to the TGFbeta receptor". Cell. 95 (6): 779–791. doi:10.1016/S0092-8674(00)81701-8. PMID9865696.