title: Homodimerization of Marek's disease virus-encoded Meq protein is not sufficient for transformation of lymphocytes in chickens.
abstract: Marek's disease virus (MDV), the etiologic agent of Marek's disease, is a potent oncogenic herpesvirus. MDV is highly contagious and elicits a rapid onset of malignant T-cell lymphomas in chickens within several weeks after infection. MDV genome codes an oncoprotein, Meq, which shares resemblance with the Jun/Fos family of bZIP transcription factors. Similar to Jun, the leucine zipper region of Meq allows the formation of homo- and heterodimers. Meq homo- and heterodimers have different DNA binding affinities and transcriptional activity; therefore, they may differentially regulate transcription of viral and cellular genes. In this study we investigated the role of Meq homodimers in the pathogenicity of MDV by generating a chimeric meq gene, which contains the leucine zipper region of the yeast transcription factor GCN4 (meqGCN). A recombinant virus (rMd5-MeqGCN) containing the chimeric meqGCN gene in place of parental meq was generated with overlapping cosmid clones of Md5, a very virulent MDV strain. The rMd5-MeqGCN virus replicated in vitro and in vivo but was unable to transform T cells in infected chickens. These data provide the first in vivo evidence that Meq homodimers are not sufficient for MDV-induced transformation.
authors.affiliation: Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: Paulette F
authors.initials: PF
authors.lastname: Suchodolski
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Izumiya
authors.forename: Blanca
authors.initials: B
authors.lastname: Lupiani
authors.forename: Dharani K
authors.initials: DK
authors.lastname: Ajithdoss
authors.forename: Oren
authors.initials: O
authors.lastname: Gilad
authors.forename: Lucy F
authors.initials: LF
authors.lastname: Lee
authors.forename: Hsing-Jien
authors.initials: HJ
authors.lastname: Kung
authors.forename: Sanjay M
authors.initials: SM
authors.lastname: Reddy
mesh_terms: D000818:Animals; D002472:Cell Transformation, Viral; D002645:Chickens; D004372:Ducks; D005347:Fibroblasts / Q000821:virology; D008214:Lymphocytes / Q000821:virology*; D025922:Mardivirus / Q000472:pathogenicity*; D008380:Marek Disease / Q000821:virology*; D015513:Oncogene Proteins / Q000378:metabolism; D011201:Poultry Diseases / Q000821:virology*; D055503:Protein Multimerization; D014764:Viral Proteins / Q000378:metabolism*; D037521:Virulence Factors / Q000378:metabolism*
chemical_list: D015513:Oncogene Proteins; D014764:Viral Proteins; D037521:Virulence Factors