Fig. 6.

Depletion of cellular AP2 or clathrin inhibits C. burnetii intracellular growth. (A) Protein expression in cells treated with targeting (+) or nontargeting (NT) (−) siRNA at 0, 1, 3, 4, or 5 d post infection (pi). HeLa cells were transfected with siRNA to deplete γ- and μ-subunits of the AP1 complex (AP1G1 and AP1M1 siRNA), β- and μ-subunits of AP2 (AP2B1 and AP2M1 siRNA), or clathrin (CLTC siRNA) and then infected with C. burnetii 2 d later (day 0 pi). Cell lysates were immunoblotted with antibodies against the AP1 γ-subunit, AP2 β-subunit, or clathrin to assess protein depletion and with antibody against GAPDH to confirm equal protein loading. (B) C. burnetii replication in HeLa cells depleted of AP1 subunits, AP2 subunits, or clathrin by siRNA. C. burnetii GEs at 1, 3, and 5 d pi were compared with GEs at day 0 pi to determine fold increases. Results are expressed as the means of two biological replicates and are representative of two independent experiments. Error bars indicate SE from the means, and an asterisk indicates a statistically significant difference (P < 0.05).