Molecular dissection of the dysferlin protein complex in skeletal
muscle
Huang, Y.
Citation
Huang, Y. (2006, September 26). Molecular dissection of the dysferlin protein complex in skeletal muscle. Gildeprint Drukkerijen, Enschede. Retrieved from
https://hdl.handle.net/1887/4573
Version: Corrected Publisher’s Version
License: Licence agreement concerning inclusion of doctoral thesis in theInstitutional Repository of the University of Leiden Downloaded from: https://hdl.handle.net/1887/4573
Summary
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Summary
M utations in dysferlin cause a number of clinically distinctmuscle diseases designated ‘dysferlinopathies’ including a proximal, limb-girdle form of muscular dystrophy (type 2B:LGM D2B) and two forms of distalmyopathy: M iyoshi myopathy (M M ) and distal myopathy with anterior tibial involvement (DM AT). To date, no correlation between the nature or location of the mutation and the clinicalphenotype has been established for these dysferlinopathies. This suggests that additional factors distinct from dysferlin butassociating with dysferlin mightbe involved.
Since dysferlin was identified as disease gene in 1998,caveolin-3,annexins, CAPN3, affixin and DHPR have been implicated to be associated with dysferlin. The work described in this thesis mainly focuses on the identification of the components of the dysferlin protein complex in order to further understand the biologicalfunction of dysferlin in muscle.
To improve the tools for understanding the pathogenesis of the dysferlinopathies, we have selected highly specific heavy chain antibody reagents against dysferlin from a non-immune llama-derived phage display library. By utilizing different truncated forms of recombinant dysferlin for selection and diverse selection strategies, antibody fragments with specificity for two different dysferlin domains could be identified. The selected llama antibody fragments were shown to be functional in W estern blotting, immunofluorescence microscopy and immunoprecipitation. Using these antibody fragments,we found thatCAPN3,which shows a secondary reduction in the dysferlinopathies, is in complex with dysferlin in skeletal muscle (chapter 2).
Summary
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marked increase and cytoplasmic localisation in regenerating rat muscle, consistent with the direct interaction between them. Data suggest that dysferlin participates in the recruitment and stabilization of AHNAK to the sarcolemma and that AHNAK plays a role in dysferlin membrane repair process (chapter 3).
