Functional interactions of the sZM domain that is mutated in zaspopathy were investigated using yeast two-hybrid, immunoprecipitation, co-sedimentation, and slot blot overlay assays. HIS-ZASP and GST-ZASP proteins were used for in vitro functional assays. ZASP-GFP cDNA were expressed in cultured C2C12 cells and in adult mouse tibialis anterior muscle by intramuscular injection. Morphology was examined with immunofluorescence and electron microscopy. We show the following results from our experiments performed during last year: 1) ZASP directly binds to skeletal muscle -actin and the conserved domain that is mutated in myopathy is important for ZASP-actin interaction. 2) Both wild type and mutant ZASP bind to -actin and -actinin, the core structure of Z-discs, but only the mutant protein causes disruption of -actinin-crosslinked actin filaments assembled in vitro, in cultured muscle cells, and in adult mouse skeletal muscle. Focal accumulations of F-actin that co-localize with ZASP are detected in patients skeletal muscle fibers. 3) The deleterious effects of the mutant ZASP are specific to the long ZASP isoform that is expressed in post-natal muscle, therefore suggesting that RNA splicing and the second actin-binding site generated thereof are modulators of the disease process. 4) We propose that mutant ZASP destabilizes the protein assemblies within cytoskeletal scaffolds that are important for maintaining the integrity of -actin lattices at the Z-discs of striated muscle. 5) Our results support dominant gain-of-function disease mechanism in zaspopathy. The above results have been submitted for a publication and is under review. We completed enrollment of subjects (n=33) to the DMD Imaging study (protocol ID 11-N-0261). We have begun the analysis of the data. Clinical observations in one of the research subjects will be published soon (see below). We have identified novel gene defects and known gene mutations in several of our patients including the ones in the Neurogenetics clinic by using NextGen exome analysis. One such research collaboration will result in a publication in near future (collaborators: Drs. Charlotte Sumner, the Johns Hopkins, and Henry Houlden, UK)

Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Zip Code
Todd, Joshua J; Razaqyar, Muslima S; Witherspoon, Jessica W et al. (2018) Novel Variants in Individuals with RYR1-Related Congenital Myopathies: Genetic, Laboratory, and Clinical Findings. Front Neurol 9:118
Jerath, Nivedita U; Mankodi, Ami; Crawford, Thomas O et al. (2018) Charcot-Marie-Tooth Disease type 4C: Novel mutations, clinical presentations, and diagnostic challenges. Muscle Nerve 57:749-755
Watts, Norman R; Zhuang, Xiaolei; Kaufman, Joshua D et al. (2017) Expression and Purification of ZASP Subdomains and Clinically Important Isoforms: High-Affinity Binding to G-Actin. Biochemistry 56:2061-2070
Kovacs, William; Hsieh, Nathan; Roth, Holger et al. (2017) Holistic segmentation of the lung in cine MRI. J Med Imaging (Bellingham) 4:041310
Mankodi, Ami; Kovacs, William; Norato, Gina et al. (2017) Respiratory magnetic resonance imaging biomarkers in Duchenne muscular dystrophy. Ann Clin Transl Neurol 4:655-662
Mankodi, Ami; Azzabou, Noura; Bulea, Thomas et al. (2017) Skeletal muscle water T2 as a biomarker of disease status and exercise effects in patients with Duchenne muscular dystrophy. Neuromuscul Disord 27:705-714
Gaur, Lasya; Hanna, Alexander; Bandettini, W Patricia et al. (2016) Upper arm and cardiac magnetic resonance imaging in Duchenne muscular dystrophy. Ann Clin Transl Neurol 3:948-955
Mankodi, Ami; Bishop, Courtney A; Auh, Sungyoung et al. (2016) Quantifying disease activity in fatty-infiltrated skeletal muscle by IDEAL-CPMG in Duchenne muscular dystrophy. Neuromuscul Disord 26:650-658
Mankodi, Ami; Grunseich, Christopher; Skov, Martin et al. (2015) Divalent cation-responsive myotonia and muscle paralysis in skeletal muscle sodium channelopathy. Neuromuscul Disord 25:908-12
Mankodi, Ami; Grunseich, Christopher (2015) Toe-extension myotonia in myotonic dystrophy type 1. Neurology 85:203

Showing the most recent 10 out of 18 publications