Figure 8

C1-associated proteins are present in CP-deficient flagella. (A) Western blot of flagella (FLA), axonemes (AXO), and the membrane + matrix fractions (M + M) isolated from WT and the CP-deficient mutants pf18 and pf19 probed with antibodies as indicated. Only traces of the C2 proteins hydin and KLP1 were detected in pf18 and pf19 flagella and both proteins were almost completely released into the detergent extract (M + M). In contrast, significant amounts of the C1 proteins PF6, CPC1, and FAP114 were present in the CP-deficient flagella and a significant proportion of these proteins remained in the axonemal fraction following detergent extraction. The outer dynein arm intermediate chain IC2 was used as a loading control. (B) To analyze the distribution of PF6 in CP-deficient flagella, methanol-fixed vegetative WT (b) and pf19 cells (a, c–i) were labeled with antibodies to PF6 and IFT139. Arrowheads (subpanel a) mark cells with a nearly symmetrical distribution of PF6 in both flagella. Note the accumulation of IFT139 in pf19 flagella compared to WT flagella. (C) The distribution of PF6 in pf15, pf18, and pf19 flagella was scored as reduced or absent (e.g. B c, d), nearly symmetrical (e.g. B e, f, g), or asymmetric (e.g. B h, i) within the two flagella of a given cell.