The heart needs to adapt its output to the metabolic demands of the organism. Phosphorylation of the myosin motors by cardiac myosin light chain kinase (cMLCK) increases heart muscle contractile function, yet its regulation and mechanism of action have remained unclear. Here, we show that cMLCK undergoes liquid-liquid phase separation and forms biomolecular condensates associated with the sarcoplasmic reticulum of cardiac muscle cells. Condensates selectively enrich enzymatic cofactors and substrates, which increases the catalytic activity of cMLCK. Our study reveals that cMLCK is fine-tuned to work in the molecular environment of condensates, enabling physiologically relevant levels of cardiac myosin motor phosphorylation. These findings establish a condensate-based mechanism for the spatial and temporal regulation of cardiac thick filament contractile function.
Wavelet analysis of human recombination rates demonstrates divergence on fine scales
Background: Recombination rates can be estimated across the genome, underpinning genetic analyses such as identification of regions under selection. Accurate recombination mapping requires observing a


