PMID- 10465067
OWN - NLM
STAT- MEDLINE
DCOM- 19991102
LR  - 20190718
IS  - 0269-9370 (Print)
IS  - 0269-9370 (Linking)
VI  - 13
IP  - 12
DP  - 1999 Aug 20
TI  - The CDK9-associated cyclins T1 and T2 exert opposite effects on HIV-1 Tat
      activity.
PG  - 1453-9
AB  - OBJECTIVES: To examine the functional interaction between HIV-1 Tat protein and
      the cyclin T1 and T2 proteins which, in association with cyclin dependent kinase 
      (CDK)9, are the regulatory subunits of the TAK/P-TEFb cellular complex strictly
      required for Tat transactivation. DESIGN: HIV-1 long terminal repeat (LTR)
      reporter plasmid was co-transfected into human and rodent cells with expression
      vectors encoding Tat and vectors encoding the cyclins T1, T2a and T2b,
      respectively. METHODS: Tat-mediated transactivation of HIV-1 LTR-driven
      transcription was compared in the presence or absence of different cyclins T (T1,
      T2a and T2b), upon co-transfections into human and rodent cell lines. Protein
      interactions were analysed by in vitro binding assays. RESULTS: It was found that
      Tat function in rodent cells is enhanced by co-expression of cyclin T1 but not
      cyclin T2. The N-terminal region (amino acids 1-290) of cyclin T1 is sufficient
      for this function and for binding to Tat and CDK9. Cyclin T2 binds to CDK9 but
      not to Tat. Moreover, enforced expression of cyclin T2 inhibits cyclin
      T1-mediated enhancement of Tat in rodent cells and it represses Tat activity in
      human cells. CONCLUSION: Efficient Tat transactivation in rodent cells occurs in 
      the presence of human cyclin T1 but not in the presence of cyclin T2;
      overexpression of cyclin T2 inhibits Tat function in both rodent and human cells.
FAU - Napolitano, G
AU  - Napolitano G
AD  - Department of Genetics, University of Naples Federico II, and International
      Institute of Genetics and Biophysics, Italy.
FAU - Licciardo, P
AU  - Licciardo P
FAU - Gallo, P
AU  - Gallo P
FAU - Majello, B
AU  - Majello B
FAU - Giordano, A
AU  - Giordano A
FAU - Lania, L
AU  - Lania L
LA  - eng
GR  - P01 NS 36466/NS/NINDS NIH HHS/United States
GR  - P01CA 56309-06/CA/NCI NIH HHS/United States
GR  - R01 CA 60999-01A1/CA/NCI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - England
TA  - AIDS
JT  - AIDS (London, England)
JID - 8710219
RN  - 0 (CCNT1 protein, human)
RN  - 0 (Cyclin T)
RN  - 0 (Cyclins)
RN  - 0 (Gene Products, tat)
RN  - 0 (Recombinant Proteins)
RN  - 0 (tat Gene Products, Human Immunodeficiency Virus)
RN  - EC 2.7.11.22 (CDK9 protein, human)
RN  - EC 2.7.11.22 (Cyclin-Dependent Kinase 9)
RN  - EC 2.7.11.22 (Cyclin-Dependent Kinases)
SB  - IM
SB  - X
MH  - Animals
MH  - CHO Cells
MH  - Cricetinae
MH  - Cyclin T
MH  - Cyclin-Dependent Kinase 9
MH  - Cyclin-Dependent Kinases/*metabolism
MH  - Cyclins/*metabolism
MH  - Gene Products, tat/*metabolism
MH  - HIV-1/*metabolism
MH  - Humans
MH  - Plasmids/genetics
MH  - Recombinant Proteins/metabolism
MH  - Terminal Repeat Sequences/genetics
MH  - Transcription, Genetic
MH  - tat Gene Products, Human Immunodeficiency Virus
EDAT- 1999/08/28 00:00
MHDA- 1999/08/28 00:01
CRDT- 1999/08/28 00:00
PHST- 1999/08/28 00:00 [pubmed]
PHST- 1999/08/28 00:01 [medline]
PHST- 1999/08/28 00:00 [entrez]
AID - 00002030-199908200-00003 [pii]
AID - 10.1097/00002030-199908200-00003 [doi]
PST - ppublish
SO  - AIDS. 1999 Aug 20;13(12):1453-9. doi: 10.1097/00002030-199908200-00003.