Drosophila small heat shock protein CryAB ensures structural integrity of developing muscles, and proper muscle and heart performance

• DOI: 10.1242/dev.115352
• Publication Date: 2015-02-27T08:11:19Z
• Authors: Inga Wójtowicz; Jadwiga Jabłońska; Monika Zmojdzian; Ouarda Taghli-Lam...; Yoan Renaud; Guillaume Junion; Malgorzata Daczewska; Sven Huelsmann; Krzysztof Jagla; Teresa Jagla
• Keywords: Myofibril; Myofilament; Desmin; Immunoprecipitation; Intercalated disc

Molecular chaperones, such as the small heat shock proteins (sHsps), maintain normal cellular function by controlling protein homeostasis in stress conditions. However, sHsps are not only activated response to environmental insults, but also exert developmental and tissue-specific functions that much less known. Here, we show during development Drosophila sHsp CryAB [L(2)efl] is specifically expressed larval body wall muscles accumulates at level of Z-bands around myonuclei. features a conserved actin-binding domain and, when attenuated, leads clustering myonuclei an altered pattern sarcomeric actin Z-band-associated crosslinker Cheerio (filamin). Our data suggest form complex essential for muscle integrity: colocalizes with revealed mass spectrometry co-immunoprecipitation experiments, binds Cheerio, muscle-specific attenuation cheerio CryAB-like phenotypes. Furthermore, muscle-targeted expression CryABR120G, which carries mutation associated desmin-related myopathy (DRM), results pattern, affected myofibrillar integrity Z-band breaks, leading reduced performance marked cardiac arrhythmia. Taken together, demonstrate ensures propose it does so interacting Cheerio. The evidence DRM-causing affects DRM-like phenotypes fly reveals stress-independent role maintaining cell cytoarchitecture.