TY - JOUR
T1 - SIMPLE binds specifically to PI4P through SIMPLE-like domain and participates in protein trafficking in the trans-Golgi network and/or recycling endosomes
AU - Moriwaki, Yasuhiro
AU - Ohno, Yuho
AU - Ishii, Tomohiro
AU - Takamura, Yuki
AU - Kita, Yuko
AU - Watabe, Kazuhiko
AU - Sango, Kazunori
AU - Tsuji, Shoutaro
AU - Misawa, Hidemi
N1 - Funding Information:
This work was supported in part by JSPS KAKENHI Grant Number 15K21370 (Y.M.) and 16K15129 (H.M.), MEXT KAKENHI Grant Number 25293020 (H.M.), MEXT-Supported Program for the Strategic Research Foundation at Private Universities 2014-2016 (H.M.), Smoking Research Foundation (H.M.). We would like to thank Editage (www.editage.jp) for English language editing.
Publisher Copyright:
© 2018 Moriwaki et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2018/6
Y1 - 2018/6
N2 - Small integral membrane protein of the lysosome/late endosome (SIMPLE) is a 161-amino acid cellular protein that contains a characteristic C-terminal domain known as the SIMPLE-like domain (SLD), which is well conserved among species. Several studies have demonstrated that SIMPLE localizes to the trans-Golgi network (TGN), early endosomes, lysosomes, multivesicular bodies, aggresomes and the plasma membrane. However, the amino acid regions responsible for its subcellular localization have not yet been identified. The SLD resembles the FYVE domain, which binds phosphatidylinositol (3)-phosphate (PI3P) and determines the subcellular localization of FYVE domain-containing proteins. In the present study, we have found that SIMPLE binds specifically to PI4P through its SLD. SIMPLE colocalized with PI4P and Rab11, a marker for recycling endosomes (REs, organelles enriched in PI4P) in both the IMS32 mouse Schwann cell line and Hela cells. Sucrose density-gradient centrifugation revealed that SIMPLE co-fractionated with syntaxin-6 (a TGN marker) and Rab11. We have also found that SIMPLE knockdown impeded recycling of transferrin and of transferrin receptor. Our overall results indicate that SIMPLE may regulate protein trafficking physiologically by localizing to the TGN and/or REs by binding PI4P.
AB - Small integral membrane protein of the lysosome/late endosome (SIMPLE) is a 161-amino acid cellular protein that contains a characteristic C-terminal domain known as the SIMPLE-like domain (SLD), which is well conserved among species. Several studies have demonstrated that SIMPLE localizes to the trans-Golgi network (TGN), early endosomes, lysosomes, multivesicular bodies, aggresomes and the plasma membrane. However, the amino acid regions responsible for its subcellular localization have not yet been identified. The SLD resembles the FYVE domain, which binds phosphatidylinositol (3)-phosphate (PI3P) and determines the subcellular localization of FYVE domain-containing proteins. In the present study, we have found that SIMPLE binds specifically to PI4P through its SLD. SIMPLE colocalized with PI4P and Rab11, a marker for recycling endosomes (REs, organelles enriched in PI4P) in both the IMS32 mouse Schwann cell line and Hela cells. Sucrose density-gradient centrifugation revealed that SIMPLE co-fractionated with syntaxin-6 (a TGN marker) and Rab11. We have also found that SIMPLE knockdown impeded recycling of transferrin and of transferrin receptor. Our overall results indicate that SIMPLE may regulate protein trafficking physiologically by localizing to the TGN and/or REs by binding PI4P.
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U2 - 10.1371/journal.pone.0199829
DO - 10.1371/journal.pone.0199829
M3 - Article
C2 - 29953492
AN - SCOPUS:85049215845
SN - 1932-6203
VL - 13
JO - PLoS One
JF - PLoS One
IS - 6
M1 - e0199829
ER -