Open AccessHnRNP U mediates the long-range regulation of Shh expression during limb development
Author(s) -
Jing Zhao,
Jun Ding,
Yingqian Li,
Kai Ren,
Jiahao Sha,
Min–Sheng Zhu,
Xiang Gao
Publication year - 2009
Publication title -
human molecular genetics online/human molecular genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.811
H-Index - 276
eISSN - 1460-2083
pISSN - 0964-6906
DOI - 10.1093/hmg/ddp250
Subject(s) - biology , nuclear matrix , enhancer , chromatin immunoprecipitation , microbiology and biotechnology , gene , regulation of gene expression , chromatin , point mutation , untranslated region , mutant , gene expression , genetics , promoter , messenger rna
Transcriptional modulation may be mediated by cis-regulatory elements distant from their target genes. Mutations in a conserved locus about 1 Mb upstream of the Shh coding region often affect Shh expression and are associated with preaxial polydactyly (PPD) defects. To understand the molecular mechanism, we analyzed a novel mouse PPD model with a T-to-A point mutation in this distant locus. A core element of mutation (CEM) with putative enhancer activity was identified by promoter activity assay and shown to contain a matrix attachment region. HnRNP U preferentially bound to the mutant but not the wild-type CEM. Interestingly, HnRNP U also bound to the 5'-UTR of the Shh gene, which was not located in the nuclear matrix in wild-type embryonic cells, as indicated by chromatin immunoprecipitation. We propose that the 5'-UTR of Shh was pulled into the nuclear matrix by HnRNP U when the CEM was mutated, and consequently affected Shh expression. Therefore, distant cis-elements may modulate gene expression by altering HnRNP U's affinity for certain mediator proteins and nuclear relocation.