SERINE PALMITOYLTRANSFERASE (SCS1 LCB2) MUTANTS HAVE ELEVATED COPY NUMBER OF THE L-A DSRNA VIRUS/

The microsomal fraction isolated from serine palmitoyltransferase (lcb 2/scs1) mutants is enriched in a 90 kDa protein. The protein was ident ified as the major coat (Gag) protein of the L-A dsRNA virus particles by partial sequencing and by its interaction with anti-Gag antibodies . The total amount of Gag in whole-cell lysates of scs1/lcb2 mutant ce lls is greater than in wild-type lystes indicating that the enrichment of the protein in the microsomal fraction of scs1/lcb2 mutant cells m ay result from increased copy number of the L-A dsRNA virus. This is s upported by the finding that the mutants also have increased levels of L-A dsRNA. Altered sphingolipid synthesis in the scs1 mutant cells ap pears to increase the copy number of the L-A viral particles. ((C) 199 7 by John Wiley & Sons, Ltd.)