Cyclin K/CPR4 inhibits primate lentiviral replication by inactivating Tat/positive transcription elongation factor b-dependent long terminal repeat transcription.
The positive transcription elongation factor b complexes comprise CDK9 and a C-type cyclin, required for the efficient expression of both eukaryotic and primate lentivirus-encoded genes. Cyclin K/CPR4 is the least studied of the positive transcription elongation factor b-forming cyclins. Here, we demonstrate that cyclin K/CPR4-containing positive transcription elongation factor b complexes are unresponsive to Tat and HEXIM1-mediated inactivation. Enhancing expression of cyclin K/CPR4 inhibited the human and simian immunodeficiency viral replication. These data indicate that cyclin K/CPR4 functions as a natural inhibitor of primate lentiviruses.
AIDS Research Center, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan.
Emiko
E
Urano
Saki
S
Shimizu
Yuko
Y
Futahashi
Makiko
M
Hamatake
Yuko
Y
Morikawa
Naoko
N
Takahashi
Hidesuke
H
Fukazawa
Naoki
N
Yamamoto
Jun
J
Komano
D000818:Animals; D016213:Cyclins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004261:DNA Replication / Q000235:genetics; D016325:HIV Long Terminal Repeat / Q000235:genetics; D015497:HIV-1 / Q000235:genetics; D006801:Humans; D017958:Lentiviruses, Primate / Q000235:genetics*; D042925:Positive Transcriptional Elongation Factor B / Q000037:antagonists & inhibitors*; D016601:RNA-Binding Proteins / Q000494:pharmacology*; D014157:Transcription Factors; D014158:Transcription, Genetic; D014779:Virus Replication / Q000235:genetics; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000494:pharmacology*
D016213:Cyclins; C476123:HEXIM1 protein, human; D016601:RNA-Binding Proteins; D014157:Transcription Factors; D054322:tat Gene Products, Human Immunodeficiency Virus; D042925:Positive Transcriptional Elongation Factor B