Placement of Leucine Zipper Motifs at the Carboxyl Terminus of HIV-1 Protease Significantly Reduces Virion Production

Pan, Yen-Yu; Wang, Shiu-Mei; Huang, Kuo-Jung; Chiang, Chien-Cheng; Wang, Chin-Tien

Although myristylation is not required for Gag-Pol viral incorporation [7, 35] , it is essential for Gag multimerization and virus assembly [11, 36] . To determine if a myristylation signal is necessary for the LZ enhancement effect on Gag cleavage, we introduced myr-into wt, Gag/PR, PRWWz, and PRKKz, and measured the Gag processing efficiency of each mutant. Our results indicate an efficient Gag processing profile for myr-PRWWz, similar to that of its myristylation-positive counterpart, PRWWz (Fig. 6 ). Since myristylation is essential to Gag membrane binding and virus assembly, we failed to detect virus-associated Gag products in any of the myr-supernatant samples (data not shown). This suggests that the LZ insertion made a significant contribution to enhanced Gag cleavage, regardless of the presence or absence of a myristylation signal.