title: NHS-A isoform of the NHS gene is a novel interactor of ZO-1.
abstract: Mutations in the NHS (Nance-Horan Syndrome) gene lead to severe congenital cataracts, dental defects and sometimes mental retardation. NHS encodes two protein isoforms, NHS-A and -1A that display cell-type dependent differential expression and localization. Here we demonstrate that of these two isoforms, the NHS-A isoform associates with the cell membrane in the presence of intercellular contacts and it immunoprecipitates with the tight junction protein ZO-1 in MDCK (Madin Darby Canine Kidney) epithelial cells and in neonatal rat lens. The NHS-1A isoform however is a cytoplasmic protein. Both Nhs isoforms are expressed during mouse development. Immunolabelling of developing mouse with the anti-NHS antibody that detects both isoforms revealed the protein in the developing head including the eye and brain. It was primarily expressed in epithelium including neural epithelium and certain vascular endothelium but only weakly expressed in mesenchymal cells. In the epithelium and vascular endothelium the protein associated with the cell membrane and co-localized with ZO-1, which indirectly indicates expression of the Nhs-A isoform in these structures. Membrane localization of the protein in the lens vesicle similarly supports Nhs-A expression. In conclusion, the NHS-A isoform of NHS is a novel interactor of ZO-1 and may have a role at tight junctions. This isoform is important in mammalian development especially of the organs in the head.
authors.affiliation: Department of Ophthalmology, Flinders University, Bedford Park, SA 5042, Australia. shiwani.sharma@flinders.edu.au
authors.forename: Shiwani
authors.initials: S
authors.lastname: Sharma
authors.forename: Katrina S Y
authors.initials: KS
authors.lastname: Koh
authors.forename: Caitlin
authors.initials: C
authors.lastname: Collin
authors.forename: Alpana
authors.initials: A
authors.lastname: Dave
authors.forename: Amy
authors.initials: A
authors.lastname: McMellon
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sugiyama
authors.forename: John W
authors.initials: JW
authors.lastname: McAvoy
authors.forename: Anne K
authors.initials: AK
authors.lastname: Voss
authors.forename: Jozef
authors.initials: J
authors.lastname: Gécz
authors.forename: Jamie E
authors.initials: JE
authors.lastname: Craig
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D004285:Dogs; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D007908:Lens, Crystalline / Q000166:cytology / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D010750:Phosphoproteins / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism; D051381:Rats; D019108:Tight Junctions / Q000378:metabolism*; D062826:Zonula Occludens-1 Protein
chemical_list: D002352:Carrier Proteins; D008565:Membrane Proteins; C542673:NHS protein, mouse; D010750:Phosphoproteins; D020033:Protein Isoforms; C569042:TJP1 protein, human; C569043:Tjp1 protein, mouse; C569044:Tjp1 protein, rat; D062826:Zonula Occludens-1 Protein