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Calcium triggers assembly of ESCRT proteins at the cell membrane
Author(s) -
Scheffer Luana Lea,
Sharma Nimisha,
Medikayala Sushma,
Brown Kristy,
Jaiswal Jyoti K
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.lb130
Subject(s) - escrt , microbiology and biotechnology , endosome , cytosol , calcium , transport protein , cell membrane , membrane protein , calcium signaling , biology , chemistry , calcium in biology , cell , intracellular , biochemistry , membrane , organic chemistry , enzyme
Intracellular calcium increase regulates variety of cellular processes, including trafficking of molecules to the plasma membrane. However, the compartments and the mechanisms involved in this trafficking are not well understood in non‐secretory cells. We have recently developed a proteomic approach that allows monitoring transient and rapid changes in the cell membrane proteome. Using this approach we have examined calcium‐triggered changes in plasma membrane proteome of muscle cells. We find that calcium increase triggers cell surface translocation of several proteins in the endosomal pathway. Notable among them are the endosomal sorting complex required for transport (ESCRT) proteins. Western blot analysis validated these proteomic findings. Using total‐internal‐reflection fluorescence microscopy of live cells we visualized calcium‐triggered cell surface translocation of fluorescently‐tagged ESCRT proteins. This showed that calcium increase triggers movement of ESCRTs directly from the cytosol to the cell membrane resulting in assembly of the late stage ESCRTs at the cell membrane. The kinetics of calcium‐induced cell membrane assembly of these ESCRTs is similar to what has been reported for virus‐induced ESCRT assembly. Our studies reveal calcium as a novel regulator of the assembly of late stage ESCRTs at the cell membrane.