Giant KASH proteins and ribosomes synergistically establish cytoplasmic biophysical properties .

Understanding how cells control their biophysical properties during development remains a fundamental challenge. While cytoplasmic macromolecular crowding affects multiple cellular processes in single cells, its regulation in living animals remains poorly understood. Using genetically encoded multimeric nanoparticles for rheology, we discovered that tissues maintain distinct cytoplasmic biophysical properties that differ from those observed across diverse systems, including bacteria, yeast species, and cultured mammalian cells.

Caenorhabditis elegans models for striated muscle disorders caused by missense variants of human LMNA.

Striated muscle laminopathies caused by missense mutations in the nuclear lamin gene LMNA are characterized by cardiac dysfunction and often skeletal muscle defects. Attempts to predict which LMNA variants are pathogenic and to understand their physiological effects lag behind variant discovery. We created Caenorhabditis elegans models for striated muscle laminopathies by introducing pathogenic human LMNA variants and variants of unknown significance at conserved residues within the lmn-1 gene.

The Nesprin-1/-2 ortholog ANC-1 regulates organelle positioning in independently from its KASH or actin-binding domains.

KASH proteins in the outer nuclear membrane comprise the cytoplasmic half of linker of nucleoskeleton and cytoskeleton (LINC) complexes that connect nuclei to the cytoskeleton. ANC-1, an ortholog of Nesprin-1/2, contains actin-binding and KASH domains at opposite ends of a long spectrin-like region. Deletion of either the KASH or calponin homology (CH) domains does not completely disrupt nuclear positioning, suggesting neither KASH nor CH domains are essential.