Cell. 1990 Oct 5;63(1):77-86. Unique Identifier : AIDSLINE MED/91004229

Two different morphogenic processes of retroviral capsid assembly have been observed: the capsid is either assembled at the plasma membrane during the budding process (type C), or preassembled within the cytoplasm (types B and D). We describe here a gag mutant of Mason-Pfizer monkey virus, a type D retrovirus, in which a tryptophan substituted for an arginine in the matrix protein results in efficient assembly of capsids at the plasma membrane through a morphogenic process similar to that of type C retroviruses. We conclude that a type D retrovirus Gag polyprotein contains an additional, dominant signal that prevents immediate transport of precursors from the site of biosynthesis to the plasma membrane. Instead, they are directed to and retained at a cytoplasmic site where a concentration sufficient for self-assembly into capsids occurs. Thus, capsid assembly processes for different retroviruses appear to differ only in the intracellular site to which capsid precursors are directed.

Amino Acid Sequence Animal Capsid/GENETICS Cell Line Clone Cells Comparative Study Gene Products, gag/GENETICS Hela Cells/METABOLISM Molecular Sequence Data Morphogenesis *Mutation Retroviridae/GROWTH & DEVELOPMENT/*GENETICS Retroviruses, Type D/GROWTH & DEVELOPMENT/*GENETICS Sequence Homology, Nucleic Acid Support, U.S. Gov't, P.H.S. Transfection Viral Matrix Proteins/*GENETICS Virion/GROWTH & DEVELOPMENT/GENETICS JOURNAL ARTICLE