The cytoplasm of striated myofibers contains a large number of membrane organelles, including sarcoplasmic reticulum (SR), T-tubules and the nuclear membrane. These organelles maintain a characteristic juxtaposition that appears to be essential for efficient inter-membranous exchange of RNA, proteins and ions. We found that the membrane-associated Muscle-specific α2/δ (Ma2/d) subunit of the Ca channel complex localizes to the SR and T-tubules, and accumulates at the myonuclear surfaces. Furthermore, mutant larval muscles exhibit nuclear positioning defects, disruption of the nuclear-SR juxtapositioning, as well as impaired larval locomotion. Ma2/d localization at the nuclear membrane depends on the proper function of the nesprin ortholog Msp300 and the BAR domain protein Amphiphysin (Amph). Importantly, live imaging of muscle contraction in intact larvae indicated altered distribution of Sarco/Endoplamic Reticulum Ca-ATPase (SERCA) around the myonuclei of mutant larvae. Co-immunoprecipitation analysis supports association between Ma2/d and Amph, and indirectly with Msp300. We therefore suggest that Ma2/d, in association with Msp300 and Amph, mediates interactions between the SR and the nuclear membrane.
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http://dx.doi.org/10.1242/dev.159558 | DOI Listing |
Eur J Nucl Med Mol Imaging
January 2025
Department of Urology, University Hospital Frankfurt, Goethe University Frankfurt Am Main, Frankfurt, Germany.
Purpose: Lutetium-177 Prostate-specific membrane antigen (Lu-PSMA) radioligand therapy is EMA-approved for metastatic castration resistant prostate cancer (mCRPC) after androgen receptor pathway inhibition (ARPI) and taxan-based chemotherapy. However, its effect in taxan-naïve patients is under current investigation.
Methods: We relied on the FRAMCAP database to elaborate Lu-PSMA therapy outcomes of progression-free (PFS) and overall (OS) in taxan-naïve mCRPC patients after previous ARPI treatment.
The nuclear pore complex (NPC), a multisubunit complex located within the nuclear envelope, regulates RNA export and the import and export of proteins. Here we address the role of the NPC in driving thermal stress-induced 3D genome repositioning of ( ) genes in yeast. We found that two nuclear basket proteins, Mlp1 and Nup2, although dispensable for NPC integrity, are required for driving genes into coalesced chromatin clusters, consistent with their strong, heat shock-dependent recruitment to gene regulatory and coding regions.
View Article and Find Full Text PDFThe cardioprotective effects of histone deacetylase (HDAC) inhibitors (HDIs) are at odds with the deleterious effects of HDAC depletion. Here, we use HDAC3 as a prototype HDAC to address this contradiction. We show that adult-onset cardiac-specific depletion of HDAC3 in mice causes cardiac hypertrophy and contractile dysfunction on a high-fat diet (HFD), excluding developmental disruption as a major reason for the contradiction.
View Article and Find Full Text PDFMechanical properties of the nucleus are remodeled not only by extracellular forces transmitted to the nucleus but also by internal modifications, such as those induced by viral infections. During herpes simplex virus type 1 infection, the viral regulation of essential nuclear functions and growth of the nuclear viral replication compartments are known to reorganize nuclear structures. However, little is known about how this infection-induced nuclear deformation changes nuclear mechanobiology.
View Article and Find Full Text PDFSoft Matter
January 2025
Laboratoire de Physique de l'École normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, F-75005 Paris, France.
Physical models of cell motility rely mostly on cytoskeletal dynamical assembly. However, when cells move through the complex 3D environment of living tissues, they have to squeeze their nucleus that is stiffer than the rest of the cell. The lamin network, organised as a shell right underneath the nuclear membrane, contributes to the nuclear integrity and stiffness.
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