title: Leucine zipper domain is required for Kaposi sarcoma-associated herpesvirus (KSHV) K-bZIP protein to interact with histone deacetylase and is important for KSHV replication.
abstract: The Kaposi sarcoma-associated herpesvirus (KSHV; or human herpesvirus-8)-encoded protein called K-bZIP (also named K8) was found to be multifunctional. In this study, we discovered that K-bZIP interacts with histone deacetylase (HDAC) 1/2 in 12-O-tetradecanoylphorbol-13-acetate-stimulated BCBL-1 lymphocyte cells. K-bZIP appears to repress HDAC activity through this interaction, which we determined to be independent of K-bZIP SUMOylation. We dissected the domains of K-bZIP and found that the leucine zipper (LZ) domain is essential for the interaction of K-bZIP and HDAC. In addition, we constructed a KSHV bacterial artificial chromosome (BAC) with LZ domain-deleted K-bZIP (KSHVdLZ) and transfected this mutated KSHV BAC DNA into HEK 293T cells. As a result, it was consistently found that K-bZIP without its LZ domain failed to interact with HDAC2. We also showed that the interaction between K-bZIP and HDAC is necessary for the inhibition of the lytic gene promoters (ORF50 and OriLyt) of KSHV by K-bZIP. Furthermore, we found that the LZ domain is also important for the interaction of K-bZIP with the promoters of ORF50 and OriLyt. Most interestingly, although it was found to have suppressive effects on the promoters of ORF50 and OriLyt, KSHVdLZ replicates at a significantly lower level than its BAC-derived revertant (KSHVdLZRev) or KSHVWT (BAC36) in HEK 293T cells. The defectiveness of KSHVdLZ replication can be partially rescued by siRNA against HDAC2. Our results suggest that the function of K-bZIP interaction with HDAC is two-layered. 1) K-bZIP inhibits HDAC activity generally so that KSHVdLZ replicates at a lower level than does KSHVWT. 2) K-bZIP can recruit HDAC to the promoters of OriLyt and ORF50 through interaction with HDAC for K-bZIP to have a temporary repressive effect on the two promoters.
authors.affiliation: Department of Microbiology/Research Centers in Minority Institutions (RCMI) Program, Ponce School of Medicine, Ponce, Puerto Rico.
authors.forename: Francisco Puerta
authors.initials: FP
authors.lastname: Martínez
authors.forename: Qiyi
authors.initials: Q
authors.lastname: Tang
mesh_terms: D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites / Q000235:genetics; D015153:Blotting, Western; D045744:Cell Line, Tumor; D004261:DNA Replication; D057809:HEK293 Cells; D019288:Herpesvirus 8, Human / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D056284:Histone Deacetylase 1 / Q000235:genetics / Q000378:metabolism*; D056464:Histone Deacetylase 2 / Q000235:genetics / Q000378:metabolism*; D054884:Host-Pathogen Interactions; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism; D016350:Leucine Zippers / Q000235:genetics; D016393:Lymphoma, B-Cell / Q000378:metabolism / Q000473:pathology / Q000821:virology; D009154:Mutation; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D034622:RNA Interference; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D058207:Sumoylation; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D017874:Immediate-Early Proteins; C118265:K8 protein, Human herpesvirus 8; D012097:Repressor Proteins; C417604:Rta protein, Human herpesvirus 8; D015534:Trans-Activators; D014764:Viral Proteins; D056284:Histone Deacetylase 1; D056464:Histone Deacetylase 2