title: Role of homeodomain-only protein in the cardiac conduction system.
abstract: Diseases of the cardiac conduction system (CCS) are a significant health issue in adult patients where few therapeutic options exist outside of expensive, device-based procedures. An evolving paradigm pointing toward several key transcription factors required for CCS development and maintenance may be a group of potential targets for reversing or treating degenerative conduction system disease. Recently, a small homeodomain-only protein (Hop) involved with regulating cardiac development has been identified, which is highly expressed in the adult murine CCS. Targeted disruption of the Hop locus leads to infra-nodal conduction defects with downregulation of connexin40 expression within the confines of the CCS. Loss of Hop does not appear to affect the size or distribution of the mature murine CCS and further studies will be required to determine whether Hop is associated with conduction system disease in humans.
authors.affiliation: Cardiovascular Institute, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.forename: Fraz A
authors.initials: FA
authors.lastname: Ismat
authors.forename: Vickas V
authors.initials: VV
authors.lastname: Patel
mesh_terms: D000818:Animals; D017630:Connexins / Q000187:drug effects; D015536:Down-Regulation / Q000187:drug effects; D006329:Heart Conduction System / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D018398:Homeodomain Proteins / Q000096:biosynthesis / Q000502:physiology* / Q000627:therapeutic use*; D006801:Humans; D025521:Tumor Suppressor Proteins / Q000096:biosynthesis / Q000502:physiology* / Q000627:therapeutic use*; D000097003:Gap Junction alpha-5 Protein
chemical_list: D017630:Connexins; D018398:Homeodomain Proteins; D025521:Tumor Suppressor Proteins; D000097003:Gap Junction alpha-5 Protein; C476884:HOPX protein, human