HJV mutants are retained into the ER. (A) HeLa cells were transiently transfected with mammalian vectors encoding WT and mutants HJV. At 18 hours after transfection, sections were stained with antibody against cMYC using nano-gold protocol as described in “Materials and methods.” Images were acquired using AnalySIS software (Soft Imaging System, Lakewood, CO). Original magnification, × 23 000. PM indicates plasma membrane; ER, endoplasmic reticulum; G, Golgi; m, mitochondria; and n, nucleus. (B) Morphometric analysis of WT and mutant HJV proteins showing the different distribution of the molecule in intracellular compartments. □ indicates ER; ⊡, Golgi apparatus; and ▪, plasma membrane. Error bars indicate SD.