International Mammalian Genome Society

17th International Mouse Genome Conference

9-12 November 2003, Braunschweig, Germany

Plenary Presentations * Oral Presentations *
Poster Presentations: Behavioural Genetics and Genomics * Development and Stem Cells * Functional Genome Analysis * Mouse Models of Human Disease * Mouse System Biology Bioinformatics * Multigenic and Multifactorial Trait Analysis * Nutrition and Metabolic Disease * Phenotyping Methods Imaging * The Genetics and Genomics of Infectious Disease *
Verne Chapman Memorial Lecture * Table of Contents * Sponsor/Exhibitor List * Awards * Photographs

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POSTER 99 - INTERACTION OF SANS, THE HUMAN USHER 1G/MOUSE JACKSON SHAKER GENE PRODUCT, WITH OTHER USHER 1 GENE PRODUCTS

Kikkawa Y
The Tokyo Metropolitan Institute of Medical Science

Co-Authors: 2) Adato A, 2) El-Amraoui A, 3) Kominami R, 2) Petit C, 1) Yonekawa H
Institutions: 1) The Tokyo Metropolitan Institute of Medical Science, 2) Institut Pasteur, 3) Niigata Graduate School of Medicine & Dental Science

Jackson shaker (js) is a deaf mouse mutant with stereocilia degeneration in its inner ear hair cells. Recently we have defined by positional cloning that the js gene encodes a new scaffold protein sans, which contains three ankyrin repeats and a SAM domain in its N- and C-terminal ends, respectively. Mutations in the human gene were found to cause syndromic deafness, Usher syndrome type IG (USH1G). Four other USH1 genes have been identified so far, encoding myosinVIIA, harmonin, cadherin23 and protocadherin15. Here, we present indications for interactions between sans and some other USH1 proteins.

As a first step toward understanding the function of sans, we have determined its expression pattern in the inner ear. Sans is widely expressed in hair cells. Interestingly, sans and myosinVIIA were found to be co-localized in the hair cells.

By yeast two-hybrid analysis we tested whether sans interacts with the other USH1 gene products, using its N- and C-terminal fragments as baits. Overlapping sequences between these baits contain the protein's central domain. Sans was found to interact with harmonin and with cadherin23. However the interaction with cadherin23 was disrupted when the ankyrin repeats were deleted from sans baits. Mice mutants deficient for any of the other USH1 proteins display similar disorganization of the stereocilia. Therefore, in light of the previously defined interactions between myosinVIIA, harmonin, and cadherin23 and the results presented in this study, we suggest that USH1 gene products cooperate in forming correct cohesion of the hair bundle.