TY - JOUR
T1 - Dynamic polyhedral actomyosin lattices remodel micron-scale curved membranes during exocytosis in live mice
AU - Ebrahim, Seham
AU - Chen, Desu
AU - Weiss, Max
AU - Malec, Lenka
AU - Ng, Yeap
AU - Rebustini, Ivan
AU - Krystofiak, Evan
AU - Hu, Longhua
AU - Liu, Jian
AU - Masedunskas, Andrius
AU - Hardeman, Edna
AU - Gunning, Peter
AU - Kachar, Bechara
AU - Weigert, Roberto
N1 - Funding Information:
This research was supported by the NIH, NCI Center for Cancer Research Intramural Research Program (ZIA BC 011682) and the NIDCD Intramural Research Program (Z01 DC 000002). We thank E. Balzer at Nikon for help with the Nikon spinning-disc microscope, C. Combs at the NHLBI Light Microscopy Core for help with the STED microscope, I. Belyansteva at the NIDCD for help with the Zeiss Airyscan microscope and R. Cui for general laboratory help.
Publisher Copyright:
© 2019, The Author(s), under exclusive licence to Springer Nature Limited.
PY - 2019/8/1
Y1 - 2019/8/1
N2 - Actomyosin networks, the cell’s major force production machineries, remodel cellular membranes during myriad dynamic processes1,2 by assembling into various architectures with distinct force generation properties3,4. While linear and branched actomyosin architectures are well characterized in cell-culture and cell-free systems3, it is not known how actin and myosin networks form and function to remodel membranes in complex three-dimensional mammalian tissues. Here, we use four-dimensional spinning-disc confocal microscopy with image deconvolution to acquire macromolecular-scale detail of dynamic actomyosin networks in exocrine glands of live mice. We address how actin and myosin organize around large membrane-bound secretory vesicles and generate the forces required to complete exocytosis5–7. We find that actin and non-muscle myosin II (NMII) assemble into previously undescribed polyhedral-like lattices around the vesicle membrane. The NMII lattice comprises bipolar minifilaments8–10 as well as non-canonical three-legged configurations. Using photobleaching and pharmacological perturbations in vivo, we show that actomyosin contractility and actin polymerization together push on the underlying vesicle membrane to overcome the energy barrier and complete exocytosis7. Our imaging approach thus unveils a force-generating actomyosin lattice that regulates secretion in the exocrine organs of live animals.
AB - Actomyosin networks, the cell’s major force production machineries, remodel cellular membranes during myriad dynamic processes1,2 by assembling into various architectures with distinct force generation properties3,4. While linear and branched actomyosin architectures are well characterized in cell-culture and cell-free systems3, it is not known how actin and myosin networks form and function to remodel membranes in complex three-dimensional mammalian tissues. Here, we use four-dimensional spinning-disc confocal microscopy with image deconvolution to acquire macromolecular-scale detail of dynamic actomyosin networks in exocrine glands of live mice. We address how actin and myosin organize around large membrane-bound secretory vesicles and generate the forces required to complete exocytosis5–7. We find that actin and non-muscle myosin II (NMII) assemble into previously undescribed polyhedral-like lattices around the vesicle membrane. The NMII lattice comprises bipolar minifilaments8–10 as well as non-canonical three-legged configurations. Using photobleaching and pharmacological perturbations in vivo, we show that actomyosin contractility and actin polymerization together push on the underlying vesicle membrane to overcome the energy barrier and complete exocytosis7. Our imaging approach thus unveils a force-generating actomyosin lattice that regulates secretion in the exocrine organs of live animals.
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U2 - 10.1038/s41556-019-0365-7
DO - 10.1038/s41556-019-0365-7
M3 - Letter
C2 - 31358965
AN - SCOPUS:85069904269
SN - 1465-7392
VL - 21
SP - 933
EP - 939
JO - Nature cell biology
JF - Nature cell biology
IS - 8
ER -