MEMBRANE JUNCTIONS ASSOCIATED WITH RUBELLA-VIRUS INFECTED-CELLS

Striking changes in membrane systems occur in the vicinity of replicat ion complexes and mitochondria in rubella virus (RV) infected Vero cel ls. An electron-dense zone about 22-25 nm in thickness fuses membranes in 3 configurations: between the outer membrane of a mitochondrion an d one membrane of the rough endoplasmic reticulum (RER), between the o uter membranes of two adjacent mitochondria, and between two apposing membranes of the RER. These junctions were called confronting membrane s type 1 (CM-1), confronting membranes type 2 (CM-2) and confronting c isternae (CC), respectively. CM-1, CM-2 and CC were not observed in mo ck infected or Semliki Forest virus (SFV) infected cells. However, mit ochondria were found to cluster around replication complexes in both S FV and RV infected cells. This suggests that replication complexes are sites of high energy requirement because of their key role in virus r eplication. The electron-dense zones appear to create almost continuou s links between RV replication complexes and mitochondria.