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Meltrin β (ADAM19) mediates ectodomain shedding of Neuregulin β1 in the Golgi apparatus: fluorescence correlation spectroscopic observation of the dynamics of ectodomain shedding in living cells
Author(s) -
Yokozeki Tomoichi,
Wakatsuki Shuji,
Hatsuzawa Kiyotaka,
Black Roy A.,
Wada Ikuo,
SeharaFujisawa Atsuko
Publication year - 2007
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1111/j.1365-2443.2007.01060.x
Subject(s) - ectodomain , golgi apparatus , disintegrin , biology , microbiology and biotechnology , neuregulin 1 , proteases , neuregulin , biophysics , brefeldin a , adam10 , biochemistry , metalloproteinase , endoplasmic reticulum , matrix metalloproteinase , enzyme , signal transduction , receptor
Membrane‐anchored Neuregulin β1 sheds its ectodomain as soluble factors. Two proteases that belong to a disintegrin and metalloprotease (ADAM) family are known to cleave Neuregulin β1. One is tumor necrosis factor‐α converting enzyme (TACE/ADAM17). The other is Meltrin β (ADAM19). Against our expectation that shedding by ADAM proteases occurs at the cell surface, here we found that Meltrin β mediates the ectodomain shedding of Neuregulin β1 in the Golgi apparatus. Meltrin β was localized in and around the Golgi apparatus in developing sensory neurons. Subcellular fractionation revealed that Meltrin β generated soluble Neuregulin β1 in Golgi‐enriched fractions while TACE‐cleaved Neuregulin β1 was recovered in lighter fractions. To examine whether Meltrin β‐mediated ectodomain shedding occurs in the Golgi apparatus in living cells, we took advantage of different diffusion properties of cleavage products from those of membrane‐anchored precursor proteins. Fluorescence correlation spectroscopy (FCS) is the most sensitive method to determine milli∼submillisecond diffusion in vivo. Protease‐active Meltrin β caused a shift in autocorrelation function in FCS of green fluorescent protein (GFP)‐tagged Neuregulin β1 in the Golgi apparatus, suggesting a conversion of Neuregulin β1 molecules from membrane‐anchored to soluble forms in that organelle. The Golgi apparatus is a site of processing Neuregulin β1 by Meltrin β.