Human protein: cyclin-dependent kinase 9
Human protein sequence: MAKQYDSVECPFCDEVSKYEKLAKIGQGTFGEVFKARHRKTGQKVALKKVLMENEKEGFPITALREIKILQLLKHENVVNLIEICRTKASPYNRCKGSIYLVFDFCEHDLAGLLSNVLVKFTLSEIKRVMQMLLNGLYYIHRNKILHRDMKAANVLITRDGVLKLADFGLARAFSLAKNSQPNRYTNRVVTLWYRPPELLLGERDYGPPIDLWGAGCIMAEMWTRSPIMQGNTEQHQLALISQLCGSITPEVWPNVDNYELYEKLELVKGQKRKVKDRLKAYVRDPYALDLIDKLLVLDPAQRIDSDDALNHDFFWSDPMPSDLKGMLSTHLTSMFEYLAPPRRKGSQITQQSTNQSRNPATTNQTEFERVF

HIV protein: Vif
Interaction type: interacts with
Description: HIV-1 Vif interacts with CDK9 to regulate Vif-mediated G1-to-S transition and siRNA against CDK9 counteracts the transition
HIV protein sequence: MENRWQVMIVWQVDRMRIRTWKSLVKHHMYVSGKARGWFYRHHYESPHPRISSEVHIPLGDARLVITTYWGLHTGERDWHLGQGVSIEWRKKRYSTQVDPELADQLIHLYYFDCFSDSAIRKALLGHIVSPRCEYQAGHNKVGSLQYLALAALITPKKIKPPLPSVTKLTEDRWNKPQKTKGHRGSHTMNGH

HIV protein: Vpr
Interaction type: interacts with
Description: HIV-1 Vpr interacts with CDK9 through binding to HIV-1 Tat and cyclin T1 in a ternary complex, Tat-Vpr-Cyclin T1-CDK9, and enhances Tat transactivation of the viral LTR promoter
HIV protein sequence: MEQAPEDQGPQREPHNEWTLELLEELKNEAVRHFPRIWLHGLGQHIYETYGDTWAGVEAIIRILQQLLFIHFRIGCRHSRIGVTRQRRARNGASRS

HIV protein: Tat
Interaction type: inhibited by
Description: Overexpression of CDK9 or CDK9 mutants inhibits HIV-1 Tat transcriptional activation
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: P-TEFb interacts with HIV-1 Tat as part of both the HIV-1 transcription preinitiation and elongation complexes
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: binds
Description: Acetylation of HIV-1 Tat by cellular histone acetyltransferases regulates the binding of Tat to P-TEFb
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: stimulates
Description: Hsp70 and Hsp90/Cdc37 stabilize CDK9 as well as the assembly of an active P-TEFb complex which is stimulated by HIV-1 Tat during HIV-1 transcriptional activation
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: binds
Description: HIV-1 Tat competes with CIITA for the binding to P-TEFb, leading to the downregulation of MHC class II gene expression
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: The human I-mfa domain-containing protein (HIC) interacts with both P-TEFb and HIV-1 Tat, and modulates Tat transactivation of the HIV-1 LTR promoter
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: stimulates
Description: HIV-1 Tat stimulates the phosphorylation of SPT5 by P-TEFb during transactivation of the HIV-1 LTR promoter
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: regulated by
Description: P-TEFb regulates HIV-1 Tat-mediated activation of transcription through two built-in auto inhibitory mechanisms, autophosphorylation of CDK9 and cyclin T1 binding to the transcription elongation factor Tat-SF1
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: recruited by
Description: Cyclin T1 is capable of recruiting CDK9 and HIV-1 Tat to splicing factor-rich nuclear speckle regions, suggesting nuclear speckles are a site of P-TEFb and Tat function
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: activates
Description: TFIIH inhibits the phosphorylation of CDK9 in the HIV-1 transcription preinitiation complex, while HIV-1 Tat stimulates CDK9 autophosphorylation to activate transcription elongation
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: complexes with
Description: The p160 nuclear receptor co-activator GRIP1 binds to the N-terminal region of HIV-1 Tat, bridging HIV-1 LTR promoter-bound factors to the Tat-P-TEFb complex and enhancing the transactivating activity of Tat
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: cooperates with
Description: P-TEFb, Puralpha and HIV-1 Tat cooperate to activate the TNFalpha promoter
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: The growth factor granulin and the promyelocytic leukemia (PML) protein regulate HIV-1 Tat-mediated transcriptional activation by competing with the Tat interaction with cyclin T1/P-TEFb
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: binds
Description: MAQ1 and 7SK RNA interact with P-TEFb and compete with the binding of HIV-1 Tat to cyclin T1, suggesting the TAR RNA/Tat lentivirus system evolved to subvert the cellular 7SK RNA/MAQ1 system
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: stimulates
Description: HIV-1 Tat-mediated stimulation of RNA polymerase II C-terminal domain phosphorylation by P-TEFb leads to stimulation of co-transcriptional capping of HIV-1 mRNA
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: complexes with
Description: PARP1 negatively regulates HIV-1 transcription by directly competing with Tat-P-TEFb complex for binding to TAR RNA
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: activates
Description: HIV-1 Tat-induced kinase activity of P-TEFb is highly sensitive to flavopiridol, a CDK inhibitor. P-TEFb-mediated phosphorylation of RNAP II CTD, SPT5, and Tat-SF1 during HIV-1 transcription elongation is also highly sensitive to flavopiridol
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: complexes with
Description: SKIP is required for Tat transactivation in vivo and stimulates HIV-1 transcription elongation by associating with CycT1:CDK9 (P-TEFb) and Tat:P-TEFb complexes both in nuclear extracts and in recombinant Tat:P-TEFb:TAR RNA complexes in vitro
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: complexes with
Description: Cdk9, the catalytic subunit of P-TEFb, is ubiquitinated by Skp1/Cul1/F-box protein E3 ubiquitin ligase Skp2, which facilitates the formation of the RNA-protein complex between P-TEFb, Tat, and TAR, thereby enhancing Tat transactivation
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: Tat-C/EBPbeta association is mediated through cdk9, which phosphorylates C/EBPbeta. C/EBPbeta-cyclin T1 association requires the presence of cdk9
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: associates with
Description: HIV-1 Tat and P-TEFb undergo constant association and dissociation cycles with TAR and the elongating polymerase in living cells
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: HIV-1 Tat competes with HEXIM1 for binding to 7SK RNA and inhibits the formation of the P-TEFb-HEXIM1-7SK complex. Tat binds to nucleotides 10-48 of 7SK RNA
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: activates
Description: HIV-1 infection leads to activation of P-TEFb due to HIV-1 Tat-mediated release of P-TEFb from the large form
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: A La-related protein, LARP7, is associated with P-TEFb, HEXIM1/2, MEPCE, and 7SK RNA in a large stable complex form. Knockdown of LARP7 decreases the steady-state level of 7SK, but increases free P-TEFb and enhances Tat-mediated transcription
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: CDK11 depletion reduces protein expression of CDK9 and HEXIM1 and Tat transactivation of HIV-1 provirus
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: complexes with
Description: Mutant CycT1 protein containing triple T-to-A mutations in the N-terminal region (amino acids T143, T149, and T155) associates with CDK9 and HIV-1 Tat as a kinase-negative complex and blocks HIV transactivation
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: phosphorylates
Description: Undetectable CycT1 protein and un-phosphorylation of CDK9 in undifferentiated monocytes result in the lack of Tat transactivation of the LTR promoter in early viral life cycle
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: cooperates with
Description: CDK9 is involved in Tat-induced MCP-1/CCL2 gene expression in human astrocytes
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: complexes with
Description: HIV-1 Tat forms at least two distinct P-TEFb-containing complexes. Tatcom1 is composed of P-TEFb, AF9, ENL, ELL, AFF1, AFF4, and PAF1, presenting strong CTD-kinase activity, while Tatcom2 consists of 7SK, LARP7, and MEPCE with two molecules of Tat/P-TEFb
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: cooperates with
Description: HIV-1 Tat increases the amount of ELL2 bound to P-TEFb without affecting the AFF4-P-TEFb binding. CDK9 is required for the Tat-induced ELL2 accumulation and Tat interaction with ELL2
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: cooperates with
Description: Interaction of P-TEFb with histone H1 results in its phosphorylation at position Ser-183 in a Tat-dependent manner, which is necessary for transcription from the HIV-1 LTR
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: binds
Description: TAR binds Tat and P-TEFb as it emerges on the nascent transcript, competitively displacing the inhibitory 7SK snRNP (HEXIM1 and LARP7) and activating the P-TEFb kinase
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: induces release of
Description: The P-TEFb binding region (amino acids 1209-1362) of BRD4 is required for HIV-1 Tat-mediated release of P-TEFb from the 7SK snRNP
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: induces release of
Description: HIV-1 Tat-mediated release of P-TEFb from the 7SK sn RNP results in a conformational change in 7SK RNA and release of HEXIM1 from the complex
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: Inhibition of Ca(2+) signaling leads to dephosphorylation of Thr186 on CDK9, which results in the decreased transactivation of the HIV-1 LTR by HIV-1 Tat
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: binds
Description: HIV-1 Q35L mutant fails to efficiently bind either CDK9 or CycT1 resulting in the defective gene expression. However, the I39Q mutation rescues the Q35L mutant's loss of function
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: ATP analogs are effective inhibitors of HIV-1 Tat-mediated activated transcription with a decreased loading of CDK9 onto the HIV-1 DNA
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: complexes with
Description: An RNA-binding domain deficient Tat excludes wild-type Tat from the promoter by preferentially assembling with P-TEFb through the Tat activation domain, but can not facilitate transfer of P-TEFb to TAR, thus blocking transition to elongation
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: Coexpression of RNA-binding domain deficient Tat (T-RS) and two fusion proteins CycT1N-Rev and Cdk9-Rev synergistically stimulates transcription when P-TEFb is tethered to RNA through Rev, and thus T-RS is no longer as an inhibitor
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: HIV-1 Tat mutations at positions P3, P6, W11, K12, T20, T23, V36, I39, T40, and Y47 show decreased Tat activity and P-TEFb assembly/Cdk9 activation, with three residues P3, P6, and W11 possibly involved in Cdk9 interactions
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: complexes with
Description: HIV-1 Tat mutations at positions Y26 and K28 show the most defect in the Tat:TAR:P-TEFb complex formation, but Tat:P-TEFb assembly is not abolished
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: induces phosphorylation of
Description: JQ1, a small molecule inhibitor of Brd4, increases CDK9 T-loop phosphorylation in Tat-dependent manner and partially dissociates P-TEFb from 7SK snRNP in Jurkat cells
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: competes with
Description: Brd4 inhibits HIV-1 Tat-human super elongation complex (components AFF4, ELL2, CycT1, and CDK9) by competing with HIV-1 Tat for binding to P-TEFb on HIV-1 promoter
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: CDK2 regulates HIV-1 Tat-mediated transcription by phosphorylation of CDK9 at position Ser90 and decreases 7SK RNA levels
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: complexes with
Description: Small molecule ligands disrupt the CDK9/Cyclin T1/Tat complex and dissociate CDK9 away from the HIV-1 transcription complex
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: binds
Description: Phosphorylation of CDK9 at position Ser175 regulates the competition between HIV-1 Tat and BRD4 for P-TEFb binding
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: ZASC1, a cellular transcription factor, interacts with HIV-1 Tat and cellular proteins CDK9/Cyclin T1 (P-TEFb) in a TAR-independent manner, suggesting that the Tat/P-TEFb complex in the transcriptional elongation site is promoted by ZASC1
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: recruits
Description: The interaction of Tip110 with HIV-1 Tat and the RNAPII C-terminal domain leads to the recruitment of increased CDK9/CycT1 to the transcription complex
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: induces release of
Description: HIV-1 Tat recruits PPM1G phosphatase protein to dephosphorylate the T loop of CDK9 and release P-TEFb from the 7SK snRNP complex
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: Binding of isolated AFF1(1-308) CBS to CDK9/CycT1 prevents HIV-1 Tat from activating HIV transcription and assembling complete SECs (AFF1, AFF4, ELL2, and ENL). The AFF1(1-308) M60A/L61A mutant shows no suppression of Tat transactivation
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: stimulates
Description: CDK9-CycT1-AFF1 is stimulated by HIV-1 Tat and transferred as a single complex unit to BRD4 upon stress-induced disruption of AFF1-containing 7SK snRNP (HEXIM1, MEPCE, LARP7, 7SK RNA, CDK9, CycT1, and AFF1)
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: AFF1 enhances the affinity of HIV-1 Tat for CycT1, which competitively dissociates HEXIM1 and is responsible for AFF1's promotion of Tat's extraction of CDK9/CycT1 from 7SK snRNP
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: complexes with
Description: The Tat-AFF4-P-TEFb complex containing HIV-1 Tat (residues 1-48), human Cyclin T1 (residues 1-266), human Cdk9 (residues 7-332), and human AFF4 (residues 27-69) is determined by the crystal structure analysis
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: The interaction of HIV-1 Tat with cellular transcription factors CDK9 and Sp1 is required for Tat activation of MAP2K3-, MAP2K6-, and IRF7-mediated luciferase transcription
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: complexes with
Description: A homogeneous assay in AlphaLISA indicates that the affinity between HIV-1 Tat and pTEFb is determined to be approximately 20pM, and only 7% of purified Tat is found to be active in forming tertiary complex with pTEFb
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: interacts with
Description: Cyclin-dependent kinase 9 (CDK9, CDC2-related kinase) is identified to interact with HIV-1 Tat mutant Nullbasic in HeLa cells by LC MS/MS
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: binds
Description: Binding of HIV-1 Tat to CDK9 stabilizes hydrogen bonds between ATP and residues Lys48, Asp104, and Cys106 and facilitates the salt bridge network pertaining to the phosphorylated Thr186 at the activation loop
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: binds
Description: HIV-1 Tat binds to CDK9 and CCNT1 (CycT1) in an additive manner as shown through Fluoppi (fluorescent-based technology detecting protein-protein interactions)
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: binds
Description: The N-terminus (amino acids 1-48, including activation domain) of HIV-1 Tat binds to P-TEFb through a direct interaction with the N-terminus (amino acids 1-290) of cyclin T1 during Tat-mediated transactivation of the HIV-1 LTR promoter
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: stimulates
Description: During HIV-1 Tat mediated transactivation of the HIV-1 LTR promoter, Tat stimulates the phosphorylation of the C-terminal domain (CTD) of RNA polymerase II by P-TEFb, leading to transcription elongation
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: recruits
Description: HIV-1 Tat recruits P-TEFb to the HIV-1 Transcription Activation Response (TAR) RNA during Tat-mediated transactivation of the HIV-1 LTR promoter
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: complexes with
Description: Tat-SF1 is a required cofactor for HIV-1 Tat activity that complexes with P-TEFb and Tat, and stimulates Tat-mediated activation of the HIV-1 LTR promoter
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: requires
Description: P-TEFb is required for HIV-1 Tat-mediated transcriptional activation
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: regulated by
Description: The up and downregulation of expression of CDK9 and cyclin T1 or sequestration of cyclin T1 in infected cells may regulate HIV-1 latency by up or downregulating HIV-1 Tat transcriptional activation
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: enhanced by
Description: The interaction of HIV-1 Tat with HIV-1 Transcription Activation Response (TAR) RNA is enhanced by the interaction of Tat with P-TEFb, and TAR RNA also enhances the interaction between Tat and cyclin T1
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Tat
Interaction type: binds
Description: Amino acids 260-263 of cyclin T1 are critical for HIV-1 Tat-mediated transcriptional activation, and mediate the species specificity of cyclin T1 and P-TEFb binding to Tat
HIV protein sequence: MEPVDPRLEPWKHPGSQPKTACTNCYCKKCCFHCQVCFITKALGISYGRKKRRQRRRAHQNSQTHQASLSKQPTSQPRGDPTGPKE

HIV protein: Nef
Interaction type: upregulates
Description: CDK9 mRNA and kinase activity are upregulated in HIV-1 Nef-expressing human T cell lines
HIV protein sequence: MGGKWSKSSVIGWPTVRERMRRAEPAADRVGAASRDLEKHGAITSSNTAATNAACAWLEAQEEEEVGFPVTPQVPLRPMTYKAAVDLSHFLKEKGGLEGLIHSQRRQDILDLWIYHTQGYFPDWQNYTPGPGVRYPLTFGWCYKLVPVEPDKIEEANKGENTSLLHPVSLHGMDDPEREVLEWRFDSRLAFHHVARELHPEYFKNC

HIV protein: Nef
Interaction type: interacts with
Description: HIV-1 Nef interacts with Hsp40, leading to increased Hsp40 translocation to the nucleus of infected cells and facilitation of viral gene expression by complex formation of Hsp40 with the cdk9-associated transcription complex
HIV protein sequence: MGGKWSKSSVIGWPTVRERMRRAEPAADRVGAASRDLEKHGAITSSNTAATNAACAWLEAQEEEEVGFPVTPQVPLRPMTYKAAVDLSHFLKEKGGLEGLIHSQRRQDILDLWIYHTQGYFPDWQNYTPGPGVRYPLTFGWCYKLVPVEPDKIEEANKGENTSLLHPVSLHGMDDPEREVLEWRFDSRLAFHHVARELHPEYFKNC

HIV protein: Nef
Interaction type: interacts with
Description: HIV-1 Nef induces cyclin K interaction with CDK9, which contributes to the inhibition of CDK9 nuclear translocation
HIV protein sequence: MGGKWSKSSVIGWPTVRERMRRAEPAADRVGAASRDLEKHGAITSSNTAATNAACAWLEAQEEEEVGFPVTPQVPLRPMTYKAAVDLSHFLKEKGGLEGLIHSQRRQDILDLWIYHTQGYFPDWQNYTPGPGVRYPLTFGWCYKLVPVEPDKIEEANKGENTSLLHPVSLHGMDDPEREVLEWRFDSRLAFHHVARELHPEYFKNC