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Deficiency of Anoctamin 5/TMEM16E causes nuclear positioning defect and impairs Ca(2+) signaling of differentiated C2C12 myotubes

Anoctamin 5 (ANO5)/TMEM16E belongs to a member of the ANO/TMEM16 family member of anion channels. However, it is a matter of debate whether ANO5 functions as a genuine plasma membrane chloride channel. It has been recognized that mutations in the ANO5 gene cause many skeletal muscle diseases such as...

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Detalles Bibliográficos
Autores principales: Phuong, Tam Thi Thanh, An, Jieun, Park, Sun Hwa, Kim, Ami, Choi, Hyun Bin, Kang, Tong Mook
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Korean Physiological Society and The Korean Society of Pharmacology 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6819897/
https://www.ncbi.nlm.nih.gov/pubmed/31680776
http://dx.doi.org/10.4196/kjpp.2019.23.6.539
Descripción
Sumario:Anoctamin 5 (ANO5)/TMEM16E belongs to a member of the ANO/TMEM16 family member of anion channels. However, it is a matter of debate whether ANO5 functions as a genuine plasma membrane chloride channel. It has been recognized that mutations in the ANO5 gene cause many skeletal muscle diseases such as limb girdle muscular dystrophy type 2L (LGMD2L) and Miyoshi muscular dystrophy type 3 (MMD3) in human. However, the molecular mechanisms of the skeletal myopathies caused by ANO5 defects are poorly understood. To understand the role of ANO5 in skeletal muscle development and function, we silenced the ANO5 gene in C2C12 myoblasts and evaluated whether it impairs myogenesis and myotube function. ANO5 knockdown (ANO5-KD) by shRNA resulted in clustered or aggregated nuclei at the body of myotubes without affecting differentiation or myotube formation. Nuclear positioning defect of ANO5-KD myotubes was accompanied with reduced expression of Kif5b protein, a kinesin-related motor protein that controls nuclear transport during myogenesis. ANO5-KD impaired depolarization-induced [Ca(2+)]i transient and reduced sarcoplasmic reticulum (SR) Ca(2+) storage. ANO5-KD resulted in reduced protein expression of the dihydropyridine receptor (DHPR) and SR Ca(2+)-ATPase subtype 1. In addition, ANO5-KD compromised co-localization between DHPR and ryanodine receptor subtype 1. It is concluded that ANO5-KD causes nuclear positioning defect by reduction of Kif5b expression, and compromises Ca(2+) signaling by downregulating the expression of DHPR and SERCA proteins.