Duchenne muscular dystrophy (DMD) is an X-linked, degenerative muscle disease that exacerbated by secondary inflammation. Here, we characterized the immunological milieu of dystrophic in mdx mice, a model DMD, to identify potential therapeutic targets. We identified specific subpopulation cells expressing Vβ8.1/8.2 TCR predominant among TCR-β+ T cells. These expressed high levels osteopontin (OPN), cytokine promotes immune cell migration and survival. Elevated OPN correlated with process,...

Interferon-induced transmembrane proteins (IFITMs) restrict infections by many viruses, but a subset of IFITMs enhance specific coronaviruses through currently unknown mechanisms. We show that SARS-CoV-2 Spike-pseudotyped virus and genuine are generally restricted human mouse IFITM1, IFITM2, IFITM3, using gain- loss-of-function approaches. Mechanistically, restriction occurred independently IFITM3 S-palmitoylation, indicating restrictive capacity distinct from reported inhibition other...

Mutations in the E3 ubiquitin ligase tripartite motif-containing 32 (TRIM32) are responsible for disease limb-girdle muscular dystrophy 2H (LGMD2H). Previously, we generated Trim32 knockout mice (Trim32-/- mice) and showed that they display a myopathic phenotype accompanied by neurogenic features. Here, used these to investigate muscle-specific defects arising from absence of TRIM32, which underlie phenotype. Using 2 models induced atrophy, TRIM32 is dispensable muscle atrophy. Conversely,...

Mutations in the non-lysosomal cysteine protease calpain 3 cause limb-girdle muscular dystrophy type 2A (LGMD2A). Our previous studies of knockout mouse (C3KO) suggested a role for sarcomere formation and remodeling. Calpain may mediate remodeling by cleavage release myofibrillar proteins, targeting them ubiquitination proteasomal degradation. Loss proper protein turnover be basis this muscle disease. To test hypothesis vivo, we used an experimental model hindlimb unloading reloading that...

Limb-girdle muscular dystrophy type 2H (LGMD2H) and sarcotubular myopathy are hereditary skeletal muscle disorders caused by mutations in TRIM32.We previously identified TRIM32 as an E3 ubiquitin ligase that binds to myosin ubiquitinates actin.To date four have been linked LGMD2H, all of which occur the C-terminal NHL domains.Unexpectedly, a fifth mutation B-box causes completely different, multisystemic disorder, Bardet -Biedl syndrome 11.It is not understood how allelic can create such...

Calpain-3 (CAPN3) is a non-lysosomal cysteine protease that necessary for normal muscle function, as mutations in CAPN3 result an autosomal recessive form of limb girdle muscular dystrophy type 2A. To elucidate the biological roles skeletal muscle, we performed search potential substrates and interacting partners. By yeast-two-hybrid analysis identified glycolytic enzyme aldolase A (AldoA) binding partner CAPN3. In co-expression studies degraded AldoA; however, no accumulation AldoA was...

A little toxin can do a lot The actin cross-linking domain (ACD) is an actin-specific produced by several bacterial pathogens. Heisler et al. discovered that ACD's pathogenic mechanism involves highly unusual toxicity amplification cascade. Rather than directly inactivating the cytoskeleton, ACD blocks activity of formins, regulatory proteins play crucial roles in numerous cellular activities. exceptionally potent, even though its substrate most abundant protein eukaryotic cell: actin....

Intracellular pH (pHi) is a fundamental component of cell homeostasis. Controlled elevations in pHi precede and accompany polarization, cytokinesis, directional migration. dysregulation contributes to cancer, neurodegenerative diseases, diabetes, other metabolic disorders. While cytoskeletal rearrangements are crucial for these processes, only few proteins, namely Cdc42, cofilin, talin, cortactin, α-actinin, AIP1 have been documented as sensors. Here, we report that actin-bundling proteins...

Abstract Calpain 3 (C3) is the only muscle‐specific member of calcium‐dependent protease family. Although neither its physiological function nor in vivo substrates are known, C3 must be an important protein for normal muscle as mutations gene result limb‐girdle muscular dystrophy type 2A. Previous reports have shown that ubiquitous calpains (μ and m) proteolyze filamins nonmuscle cells. This observation suggests filamin C (FLNC) a good candidate substrate C3. Binding studies using...

Mutations in the non-lysosomal cysteine protease calpain-3 cause autosomal recessive limb girdle muscular dystrophy. Pathological mechanisms occurring this disease have not yet been elucidated. Here, we report both morphological and biochemical evidence of mitochondrial abnormalities knockout (C3KO) muscles, including irregular ultrastructure distribution mitochondria. The C3KO muscles are associated with reduced vivo ATP production as measured by 31 P magnetic resonance spectroscopy....

The actin-binding and bundling protein, plastin 3 (PLS3), was identified as a protective modifier of spinal muscular atrophy (SMA) in some patient populations disease animal models SMA. How it functions this process, however, is not known. Because PLS3 an actin-binding/bundling we hypothesized would likely act via modification the actin cytoskeleton axons neuromuscular junctions to protect motoneurons To test this, examined ability other known organizing proteins modify motor axon outgrowth...

Abstract Mutations in actin-bundling protein plastin 3 (PLS3) emerged as a cause of congenital osteoporosis, but neither the role PLS3 bone development nor mechanisms underlying PLS3-dependent osteoporosis are understood. Of over 20 identified osteoporosis-linked mutations, we investigated all five that expected to produce full-length protein. One mutations distorted an actin-binding loop second domain and abolished F-actin bundling revealed by cryo-EM reconstruction interaction assays....

According to the cellular actin dynamics paradigm, filaments grow at their barbed ends and depolymerize predominantly from pointed form polar structures do productive work. We show that can elongate end when assisted by Vibrio VopF/L toxins, which act as processive polymerases. In cells, processively moving speckles are inhibited factors blocking but not ends. Multispectral single-molecule imaging confirmed VopF molecules associate with end, actively promoting its elongation even in presence...

The cysteine protease calpain 3 (CAPN3) is essential for normal muscle function, since mutations in CAPN3 cause limb girdle muscular dystrophy type 2A. Previously, we showed that myoblasts isolated from knockout (C3KO) mice were able to fuse myotubes; however, sarcomere formation was disrupted. In this study further characterized morphological and biochemical features of C3KO myotubes order elucidate a role during myogenesis. We cell cycle withdrawal occurred normally cultures, but have an...

Mutations in the non-lysosomal, cysteine protease calpain 3 (CAPN3) result disease limb girdle muscular dystrophy type 2A (LGMD2A). CAPN3 is localized to several subcellular compartments, including triads, where it plays a structural, rather than proteolytic, role. In absence of CAPN3, triad components are reduced, major Ca2+ release channel, ryanodine receptor (RyR). Furthermore, upon excitation impaired CAPN3. present study, we show that Ca-calmodulin protein kinase II (CaMKII) signaling...

Calpain 3 (CAPN3) is a muscle-specific, calcium-dependent proteinase that mutated in Limb Girdle Muscle Dystrophy type 2A.Most pathogenic missense mutations LGMD2A affect CAPN3's proteolytic activity; however, two mutations, D705G and R448H, retain activity but nevertheless cause muscular dystrophy.Previously, we showed R448H reduce CAPN3s ability to bind titin vitro.In this investigation, tested the consequence of loss binding vivo examined whether can be an underlying mechanism LGMD2A.To...

Mutations in tripartite motif protein 32 (TRIM32) are responsible for several hereditary disorders that include limb girdle muscular dystrophy type 2H (LGMD2H), sarcotubular myopathy (STM) and Bardet Biedl syndrome. Most LGMD2H mutations TRIM32 clustered the NHL β-propeller domain at C-terminus predicted to interfere with homodimerization. To get insight into TRIM32's role pathogenesis of create an accurate model disease, we have generated a knock-in mouse (T32KI) carrying c.1465G > A...

Limb girdle muscular dystrophy 2H is caused by mutations in the gene encoding E3 ubiquitin ligase, TRIM32. Previously, we generated and characterized a Trim32 knockout mouse (T32KO) that displays both neurogenic myopathic features. The myopathy these mice attributable to impaired muscle growth, associated with satellite cell senescence premature sarcopenia. This due accumulation of SUMO ligase PIASy, substrate goal this investigation was identify additional substrates TRIM32 using 2D...

Actin-depolymerizing factor (ADF)/cofilins accelerate actin turnover by severing aged filaments and promoting the dissociation of subunits. In cell, ADF/cofilins are assisted other proteins, among which cyclase-associated proteins 1 2 (CAP1,2) particularly important. The N-terminal half CAP has been shown to promote filament dynamics enhancing ADF-/cofilin-mediated severing, while central C-terminal domains involved in recharging depolymerized ADP–G-actin/cofilin complexes with ATP profilin....