Interaction and mutual inhibition of p97 and ATG9.
(A) The analysis of phototactic ability illustrates mutual inhibition of p97 and ATG9 in conjunction with inhibition of this process in AX2 cells. (B) Expression of p97R155C in AX2 wild-type cells frees ATG9 to exert its inhibitory activity. (C) Expression of wild-type p97 in wild-type AX2 cells results in slightly reduced phototaxis which can be explained by a dose dependent effect. (D) In the absence of ATG9, its inhibitory activity versus p97 is lost leaving p97 free to strongly inhibit phototaxis. (E) Partial rescue of phototaxis in the ATG9KO/p97R155C-RFP double mutant. (F) Since phototaxis is already lost in ATG9KO cells, the expression of p97-RFP cannot lead to a further impairment. Line width correlates with the strength of the inhibitory effect. Dotted line, residual activity. Please refer to the Discussion section for further details on this model of interaction and mutual inhibition.