RT Journal Article T1 The cell-wide web coordinates cellular processes by directing site-specific Ca2+ flux across cytoplasmic nanocourses A1 Duan, Jingxian A1 Navarro Dorado, Jorge A1 Clark, Jill A1 Kinnear, Nicholas A1 Meinke, Peter A1 Schirmer, Eric A1 Evans, Anthony Mark AB Ca2+ coordinates diverse cellular processes, yet how function-specific signals arise is enigmatic. We describe a cell-wide network of distinct cytoplasmic nanocourses with the nucleus at its centre, demarcated by sarcoplasmic reticulum (SR) junctions (≤400 nm across) that restrict Ca2+ diffusion and by nanocourse-specific Ca2+-pumps that facilitate signal segregation. Ryanodine receptor subtype 1 (RyR1) supports relaxation of arterial myocytes by unloading Ca2+ into peripheral nanocourses delimited by plasmalemma-SR junctions, fed by sarco/endoplasmic reticulum Ca2+ ATPase 2b (SERCA2b). Conversely, stimulus-specified increases in Ca2+ flux through RyR2/3 clusters selects for rapid propagation of Ca2+ signals throughout deeper extraperinuclear nanocourses and thus myocyte contraction. Nuclear envelope invaginations incorporating SERCA1 in their outer nuclear membranes demarcate further diverse networks of cytoplasmic nanocourses that receive Ca2+ signals through discrete RyR1 clusters, impacting gene expression through epigenetic marks segregated by their associated invaginations. Critically, this circuit is not hardwired and remodels for different outputs during cell proliferation. PB Nature Research YR 2019 FD 2019 LK https://hdl.handle.net/20.500.14352/115653 UL https://hdl.handle.net/20.500.14352/115653 LA eng NO Duan, J., Navarro-Dorado, J., Clark, J.H. et al. The cell-wide web coordinates cellular processes by directing site-specific Ca2+ flux across cytoplasmic nanocourses. Nat Commun 10, 2299 (2019). https://doi.org/10.1038/s41467-019-10055-w NO British Heart Foundation NO China Scholarship Council NO Wellcome Centre DS Docta Complutense RD 8 abr 2025