Mapping of the interaction site of the defective transcription factor in the class II major histocompatibility complex mutant cell line clone-13 to the divergent X2-box

S. J. Ono, Z. Song

Research output: Contribution to journalArticle

Abstract

We have previously described a mutant B lymphoblastoid cell line, Clone- 13, that expresses HLA-DQ in the absence of HLA-DR and -DP. Several criteria indicated that the defect in this cell line influences the activity of an isotype-specific transcription factor. Indeed, transient transfection of HLA- DRA and DQB reporter constructs indicated that the affected factor operates via cis-elements located between -141 base pairs and the transcription initiation site. A series of hybrid DRA/DQB reporter constructs was generated to further map the relevant cis-elements in this system. Insertion of oligonucleotides spanning the DQB X-box (but not the DQB-W region or the DQB Y-box) upstream of -141 in a DRA reporter plasmid rescued expression to nearly wild-type levels. Substitution promoters were then generated where the entire X-box, or only the X1- or X2-boxes of HLA-DRA were replaced with the analogous regions of HLA-DQB. The DQB X2-box was able to restore expression to the silent DRA reporter construct. Moreover, replacement of the DQB X2- box with the DRA X2-box markedly diminished the activity of the DQB promoter in the mutant cell. None of the hybrid reporter constructs were defective when transfected into the wild-type, HLA-DR/-DQ positive parental cell line, Jijoye. These studies suggest that the divergent X2-box of the class II major histocompatibility complex promoters plays an important role in influencing differential expression of the human class II isotypes.

Original languageEnglish (US)
Pages (from-to)6396-6402
Number of pages7
JournalJournal of Biological Chemistry
Volume270
Issue number11
DOIs
StatePublished - Jan 1 1995

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Mapping of the interaction site of the defective transcription factor in the class II major histocompatibility complex mutant cell line clone-13 to the divergent X2-box'. Together they form a unique fingerprint.

  • Cite this