title: HOXA9 methylation by PRMT5 is essential for endothelial cell expression of leukocyte adhesion molecules.
abstract: The induction of proinflammatory proteins in stimulated endothelial cells (EC) requires activation of multiple transcription programs. The homeobox transcription factor HOXA9 has an important regulatory role in cytokine induction of the EC-leukocyte adhesion molecules (ELAM) E-selectin and vascular cell adhesion molecule 1 (VCAM-1). However, the mechanism underlying stimulus-dependent activation of HOXA9 is completely unknown. Here, we elucidate the molecular mechanism of HOXA9 activation by tumor necrosis factor alpha (TNF-α) and show an unexpected requirement for arginine methylation by protein arginine methyltransferase 5 (PRMT5). PRMT5 was identified as a TNF-α-dependent binding partner of HOXA9 by mass spectrometry. Small interfering RNA (siRNA)-mediated depletion of PRMT5 abrogated stimulus-dependent HOXA9 methylation with concomitant loss in E-selectin or VCAM-1 induction. Chromatin immunoprecipitation analysis revealed that PRMT5 is recruited to the E-selectin promoter following transient HOXA9 binding to its cognate recognition sequence. PRMT5 induces symmetric dimethylation of Arg140 on HOXA9, an event essential for E-selectin induction. In summary, PRMT5 is a critical coactivator component in a newly defined, HOXA9-containing transcription complex. Moreover, stimulus-dependent methylation of HOXA9 is essential for ELAM expression during the EC inflammatory response.
authors.affiliation: Department of Cell Biology, Lerner Research Institute and Cleveland Clinic Lerner College of Medicine, Cleveland Clinic Foundation, Cleveland, Ohio, USA.
authors.forename: Smarajit
authors.initials: S
authors.lastname: Bandyopadhyay
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Harris
authors.forename: Gregory N
authors.initials: GN
authors.lastname: Adams
authors.forename: Gregory E
authors.initials: GE
authors.lastname: Lause
authors.forename: Anne
authors.initials: A
authors.lastname: McHugh
authors.forename: Emily G
authors.initials: EG
authors.lastname: Tillmaand
authors.forename: Angela
authors.initials: A
authors.lastname: Money
authors.forename: Belinda
authors.initials: B
authors.lastname: Willard
authors.forename: Paul L
authors.initials: PL
authors.lastname: Fox
authors.forename: Paul E
authors.initials: PE
authors.lastname: Dicorleto
mesh_terms: D019040:E-Selectin / Q000235:genetics* / Q000276:immunology; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D061307:Human Umbilical Vein Endothelial Cells / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D008745:Methylation; D009687:Nuclear Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics* / Q000276:immunology
chemical_list: C529705:COPRS protein, human; D019040:E-Selectin; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; C097899:homeobox protein HOXA9