title: Exhaustive identification of human class II basic helix-loop-helix proteins by virtual library screening.
abstract: Cellular proliferation, specification and differentiation in developing tissues are tightly coordinated by groups of transcription factors in response to extrinsic and intrinsic signals. Furthermore, renewable pools of stem cells in adult tissues are subject to similar regulation. Basic helix-loop-helix (bHLH) proteins are a group of transcription factors that exert such a determinative influence on a variety of developmental pathways from C. elegans to humans, and we wished to exclusively identify novel members from within the whole human bHLH family. We have, therefore, developed an 'empirical custom fingerprint', to define the class II bHLH domain and exclusively identify these proteins in silico. We have identified nine previously uncharacterised human class II proteins, four of which were novel, by interrogating conceptual translations of the GenBank HTGS database. RT-PCR and mammalian 2-hybrid analysis of a subset of the factors demonstrated that they were indeed expressed, and were able to interact with an appropriate binding partner in vitro. Thus, we are now approaching an almost complete listing of human class II bHLH factors.
authors.affiliation: Department of Clinical Biochemistry, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QR, UK. a.mclellan@ucc.ie
authors.forename: Andrew S
authors.initials: AS
authors.lastname: McLellan
authors.forename: Kenneth
authors.initials: K
authors.lastname: Langlands
authors.forename: Terence
authors.initials: T
authors.lastname: Kealey
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D018257:Helix-Loop-Helix Motifs / Q000235:genetics*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D019151:Peptide Library; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011506:Proteins / Q000145:classification* / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D019151:Peptide Library; D011506:Proteins; D014157:Transcription Factors; C471854:BHLHE22 protein, human; C491312:Bhlha15 protein, mouse; C455509:Bhlhb4 protein, mouse; C093504:SCX protein, human; C503815:Scx protein, mouse; C485762:TCF23 protein, human; C404514:Tcf23 protein, mouse