Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
2002-6-18
pubmed:abstractText
Basic helix-loop-helix (bHLH) transcription factors control developmental decisions in a wide range of embryonic cell types. The HLH motif mediates homo- and heterodimerization, which juxtaposes the basic regions within the dimeric complex to form a bipartite DNA binding domain that recognizes a DNA consensus sequence known as an E-box. eHAND and dHAND (also known as HAND1 and HAND2) are closely related bHLH proteins that control cardiac, craniofacial and limb development. Within the developing limb, dHAND expression encompasses the zone of polarizing activity in the posterior region, where it has been shown to be necessary and sufficient to induce the expression of the morphogen sonic hedgehog. Misexpression of dHAND in the anterior compartment of the limb bud induces ectopic expression of sonic hedgehog, with resulting preaxial polydactyly and mirror image duplications of posterior digits. To investigate the potential transcriptional mechanisms involved in limb patterning by dHAND, we have performed a structure-function analysis of the protein in cultured cells and ectopically expressed dHAND mutant proteins in the developing limbs of transgenic mice. We show that an N-terminal transcriptional activation domain, and the bHLH region, are required for E-box-dependent transcription in vitro. Remarkably, however, digit duplication by dHAND requires neither the transcriptional activation domain nor the basic region, but only the HLH motif. eHAND has a similar limb patterning activity to dHAND in these misexpression experiments, indicating a conserved function of the HLH regions of these proteins. These findings suggest that dHAND may act via novel transcriptional mechanisms mediated by protein-protein interactions independent of direct DNA binding.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Basic Helix-Loop-Helix..., http://linkedlifedata.com/resource/pubmed/chemical/DNA, http://linkedlifedata.com/resource/pubmed/chemical/DNA-Binding Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Hand2 protein, mouse, http://linkedlifedata.com/resource/pubmed/chemical/Herpes Simplex Virus Protein Vmw65, http://linkedlifedata.com/resource/pubmed/chemical/Nuclear Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Tcf15 protein, mouse, http://linkedlifedata.com/resource/pubmed/chemical/Transcription Factors, http://linkedlifedata.com/resource/pubmed/chemical/Zebrafish Proteins, http://linkedlifedata.com/resource/pubmed/chemical/hand2 protein, zebrafish, http://linkedlifedata.com/resource/pubmed/chemical/par1 protein, zebrafish
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0950-1991
pubmed:author
pubmed:issnType
Print
pubmed:volume
129
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3077-88
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:12070084-Amino Acid Sequence, pubmed-meshheading:12070084-Animals, pubmed-meshheading:12070084-Basic Helix-Loop-Helix Transcription Factors, pubmed-meshheading:12070084-Cells, Cultured, pubmed-meshheading:12070084-Conserved Sequence, pubmed-meshheading:12070084-DNA, pubmed-meshheading:12070084-DNA-Binding Proteins, pubmed-meshheading:12070084-Extremities, pubmed-meshheading:12070084-Gene Expression Regulation, Developmental, pubmed-meshheading:12070084-Helix-Loop-Helix Motifs, pubmed-meshheading:12070084-Herpes Simplex Virus Protein Vmw65, pubmed-meshheading:12070084-Limb Buds, pubmed-meshheading:12070084-Mice, pubmed-meshheading:12070084-Mice, Transgenic, pubmed-meshheading:12070084-Molecular Sequence Data, pubmed-meshheading:12070084-Mutation, pubmed-meshheading:12070084-Nuclear Proteins, pubmed-meshheading:12070084-Polydactyly, pubmed-meshheading:12070084-Transcription Factors, pubmed-meshheading:12070084-Zebrafish Proteins
pubmed:year
2002
pubmed:articleTitle
Misexpression of dHAND induces ectopic digits in the developing limb bud in the absence of direct DNA binding.
pubmed:affiliation
Department of Molecular Biology, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX 75390-9148, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't