Structural and functional characterization of H2 haplotype MAPT promoter: unique neurospecific domains and a hypoxia-inducible element would enhance rationally targeted tauopathy research for Alzheimer's disease.
Alzheimer's disease (AD) is the leading cause of dementia in the elderly. Extraneuronal plaque comprising mostly the amyloid β peptide and intraneuronal tangles of hyperphosphorylated microtubule-associated τ protein (τ, gene MAPT) are typical of AD. Misfolded τ is also implicated in Parkinson's disease and frontotemporal dementia. We aim to understand the regulation of the human MAPT promoter by mapping its functional domains. We subcloned a 4868 base pair (bp) fragment from human BAC RPCI-11 100C5. Sequence analysis revealed an H2 haplotype MAPT promoter, 5'-UTR, and intronal fragment. Database analysis of the fragment showed 50%-75% homology with mouse and >90% with rhesus monkey. Comparison with human H1 sequences revealed differences that crossed predicted transcription factor sites. DNA-protein interaction studies by electrophoretic mobility shift assay suggested hypoxia response and an active specificity protein 1 (SP1) site in the 5'-untranslated region. Transfection of a series of MAPT promoter deletions revealed unique functional domains. The distal-most had different activities in neuronal vs. non-neuronal cells. We have cloned, sequenced, and functionally characterized a 4868bp fragment of the human MAPT 5'-flanking region, including the core promoter region (-302/+4), neurospecific domains (-4364/-1992 and +293/+504, relative to +1 TSS), and a hypoxia-inducible element (+60/+84). Our work extended functional analysis of the MAPT sequence further upstream, and explores cell-type specificity of MAPT promoter activity. Finally, we provided direct comparison of likely transcription factor binding sites, which are useful to understand differences between H1/H2 pathogenic associations.
Laboratory of Molecular Neurogenetics, Department of Psychiatry, Institute of Psychiatric Research Indiana University School of Medicine, Indianapolis, IN 46202, USA.
Bryan
B
Maloney
Debomoy K
DK
Lahiri
D020121:5' Untranslated Regions; D000544:Alzheimer Disease / Q000235:genetics* / Q000473:pathology; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D024202:Electrophoretic Mobility Shift Assay; D006239:Haplotypes; D006801:Humans; D000860:Hypoxia / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D016875:tau Proteins / Q000235:genetics / Q000378:metabolism*
D020121:5' Untranslated Regions; D017931:DNA Primers; C054369:MAPT protein, human; D016875:tau Proteins