Measles virus phosphoprotein retains the nucleocapsid protein in the cytoplasm.
Measles virus (MV) proteins were efficiently expressed in COS and Vero cells from vectors based on the strong cytomegalovirus enhancer-promoter and the simian virus 40 origin of replication. When expressed alone, nucleocapsid protein (N) migrates predominantly into the nucleus whereas phosphoprotein (P) is located in the cytoplasm. Coexpression of N and P proteins results in retention of the N protein in the cytoplasm, as seen also in infected cells. The retention of N protein is due to specific interactions with the P protein since coexpression of N with either the matrix or the hemagglutinin protein had no effect. Mapping of the regions of N-P interactions on P protein revealed that the carboxy-terminal 40% of P was sufficient for specific binding to N; however, the carboxy-terminal 60% of P was required for retention of N in the cytoplasm. Thus, the V and C proteins encoded within the first half of the P gene are not involved in the cytoplasmic retention of N protein. N protein might be fortuitously targeted to the nucleus as a result of its many basic amino acids, presumably destined to interact with the MV genome. However, this set of experiments has allowed to analyze in vivo the interactions between the N and P proteins.
Huber
M
M
Institut für Molekularbiologie I, Universität Zürich.
Cattaneo
R
R
Spielhofer
P
P
Orvell
C
C
Norrby
E
E
Messerli
M
M
Perriard
J C
JC
Billeter
M A
MA
D000818:Animals; D001483:Base Sequence; D002213:Capsid / Q000235:genetics*; D002460:Cell Line; D003587:Cytomegalovirus / Q000235:genetics; D003593:Cytoplasm / Q000502:physiology; D004261:DNA Replication; D004279:DNA, Viral / Q000235:genetics; D004742:Enhancer Elements, Genetic; D005455:Fluorescent Antibody Technique; D005822:Genetic Vectors; D008459:Measles virus / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D010750:Phosphoproteins / Q000235:genetics*; D011401:Promoter Regions, Genetic; D013539:Simian virus 40 / Q000235:genetics; D014162:Transfection; D014709:Vero Cells; D014758:Viral Core Proteins / Q000235:genetics*
D004279:DNA, Viral; D009838:Oligodeoxyribonucleotides; D010750:Phosphoproteins; D014758:Viral Core Proteins