Fig. 7: Model of Khc regulation by Tm1 in osk RNPs.
From: Tropomyosin 1-I/C coordinates kinesin-1 and dynein motors during oskar mRNA transport
a, Model of Tm1-mediated stabilization of autoinhibited conformation of Khc. Whereas both the motor ___domain-IAK motif interaction and interactions within the Tm1-bound, rearranged Khc stalk region (including the AMB ___domain) can partially inhibit Khc, synergy between these weak interactions stabilizes the inhibitory head-tail interaction. b, Model of Tm1’s role in dynein-mediated transport of osk. By linking Khc to the dynein-transported osk RNA and promoting Khc inhibition, Tm1 allows the first, dynein-mediated transport step from the nurse cells to the oocyte to proceed without competition between the motors. These events also position Khc on the RNP for the second, Khc-mediated transport step within the oocyte. AAAAA and m7G indicate poly A tail and cap structure of osk, respectively.
