Upon identification of PB or stress granule
fission during postimaging analysis, a seg-
mented line was drawn perpendicular to the
PB or stress granule fission site through the
length of the PB or stress granule. The fluo-
rescence intensities of ER and PB or stress
granule channels were measured along the
length of the line for each time point and
plotted. ER-marked fission events were iden-
tified by acute decreases in PB or stress gran-
ule marker fluorescence that coincided with
mCh-KDEL (ER) fluorescence peaks.
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ACKNOWLEDGMENTS
We thank A. Khong, B. Van Treeck, E. Zamponi, R. G. Abrisch,
B. S. Rao, G. Odorizzi, and D. Buysse for helpful insights and
discussion.Funding:G.K.V. and R.P. are investigators of
the Howard Hughes Medical Institute. J.E.L. and H.W. were
supported by a grant to G.K.V. from the NIH (GM13009816).
Author contributions:J.E.L., G.K.V., and R.P. designed the
research plan and interpreted the results. J.E.L., P.I.C., and H.W.
performed and analyzed the experiments. J.E.L. wrote and R.P. and
G.K.V. edited the manuscript.Competing interests:None of
the authors have a competing interest.Data and materials
availability:All data are available in the manuscript or the
supplementary materials. The expression plasmids reported in this
manuscript are available at Addgene or upon request.SUPPLEMENTARY MATERIALS
science.sciencemag.org/content/367/6477/eaay7108/suppl/DC1
Figs. S1 to S5
View/request a protocol for this paper fromBio-protocol.13 July 2019; resubmitted 4 November 2019
Accepted 4 December 2019
10.1126/science.aay7108Leeet al.,Science 367 , eaay7108 (2020) 31 January 2020 10 of 10
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