Monomerization and ER Relocalization of GRASP Is a Requisite for Unconventional Secretion of CFTR

Jiyoon Kim; Shin Hye Noh; He Piao; Dong Hee Kim; Kuglae Kim; Jeong Seok Cha; Woo Young Chung; Hyun Soo Cho; Joo Young Kim; Min Goo Lee

doi:10.1111/tra.12403

Monomerization and ER Relocalization of GRASP Is a Requisite for Unconventional Secretion of CFTR

Jiyoon Kim, Shin Hye Noh, He Piao, Dong Hee Kim, Kuglae Kim, Jeong Seok Cha, Woo Young Chung, Hyun Soo Cho, Joo Young Kim, Min Goo Lee

Research output: Contribution to journal › Article › peer-review

50 Citations (Scopus)

Abstract

Induction of endoplasmic reticulum (ER)-to-Golgi blockade or ER stress induces Golgi reassembly stacking protein (GRASP)-mediated, Golgi-independent unconventional cell-surface trafficking of the folding-deficient ΔF508-cystic fibrosis transmembrane conductance regulator (CFTR). However, molecular mechanisms underlying this process remain elusive. Here, we show that phosphorylation-dependent dissociation of GRASP homotypic complexes and subsequent relocalization of GRASP to the ER play a critical role in the unconventional secretion of CFTR. Immunolocalization analyses of mammalian cells revealed that the Golgi protein GRASP55 was redistributed to the ER by stimuli that induce unconventional secretion of ΔF508-CFTR, such as induction of ER-to-Golgi blockade by the Arf1 mutant. Notably, the same stimuli also induced phosphorylation of regions near the C-terminus of GRASP55 and dissociation of GRASP homomultimer complexes. Furthermore, phosphorylation-mimicking mutations of GRASP55 induced the monomerization and ER relocalization of GRASP55, and these changes were nullified by phosphorylation-inhibiting mutations. These results provide mechanistic insights into how GRASP accesses the ER-retained ΔF508-CFTR and mediates the ER stress-induced unconventional secretion pathway.

Original language	English
Pages (from-to)	733-753
Number of pages	21
Journal	Traffic
Volume	17
Issue number	7
DOIs	https://doi.org/10.1111/tra.12403
Publication status	Published - 2016 Jul 1

Bibliographical note

Funding Information:
We thank Dong Soo Chang for the assistance with illustrations and the Yonsei-Carl Zeiss Advanced Imaging Center for technical assistance. This work was supported by grants 2013R1A3A2042197 and 2007–0056092 from the National Research Foundation, the Ministry of Science, ICT & Future Planning, Republic of Korea. J. K., S. H. N., H. P., D. H. K. and W. Y. C. performed molecular and immunofluorescence experiments and analyzed the data. J. S. C. and K. K. performed the surface plasmon resonance experiments. H.-S. C. and J. Y. K. contributed to data analysis. J. K., S. H. N. and M. G. L. planned the study, contributed to analysis of the data and wrote the paper. All authors discussed the results and commented on the manuscript. The authors declare no competing financial interests.

Publisher Copyright:
© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

All Science Journal Classification (ASJC) codes

Structural Biology
Biochemistry
Molecular Biology
Genetics
Cell Biology

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@article{10c3ee80947a41d5961c3c994f51a446,

title = "Monomerization and ER Relocalization of GRASP Is a Requisite for Unconventional Secretion of CFTR",

abstract = "Induction of endoplasmic reticulum (ER)-to-Golgi blockade or ER stress induces Golgi reassembly stacking protein (GRASP)-mediated, Golgi-independent unconventional cell-surface trafficking of the folding-deficient ΔF508-cystic fibrosis transmembrane conductance regulator (CFTR). However, molecular mechanisms underlying this process remain elusive. Here, we show that phosphorylation-dependent dissociation of GRASP homotypic complexes and subsequent relocalization of GRASP to the ER play a critical role in the unconventional secretion of CFTR. Immunolocalization analyses of mammalian cells revealed that the Golgi protein GRASP55 was redistributed to the ER by stimuli that induce unconventional secretion of ΔF508-CFTR, such as induction of ER-to-Golgi blockade by the Arf1 mutant. Notably, the same stimuli also induced phosphorylation of regions near the C-terminus of GRASP55 and dissociation of GRASP homomultimer complexes. Furthermore, phosphorylation-mimicking mutations of GRASP55 induced the monomerization and ER relocalization of GRASP55, and these changes were nullified by phosphorylation-inhibiting mutations. These results provide mechanistic insights into how GRASP accesses the ER-retained ΔF508-CFTR and mediates the ER stress-induced unconventional secretion pathway.",

author = "Jiyoon Kim and Noh, {Shin Hye} and He Piao and Kim, {Dong Hee} and Kuglae Kim and Cha, {Jeong Seok} and Chung, {Woo Young} and Cho, {Hyun Soo} and Kim, {Joo Young} and Lee, {Min Goo}",

note = "Funding Information: We thank Dong Soo Chang for the assistance with illustrations and the Yonsei-Carl Zeiss Advanced Imaging Center for technical assistance. This work was supported by grants 2013R1A3A2042197 and 2007–0056092 from the National Research Foundation, the Ministry of Science, ICT & Future Planning, Republic of Korea. J. K., S. H. N., H. P., D. H. K. and W. Y. C. performed molecular and immunofluorescence experiments and analyzed the data. J. S. C. and K. K. performed the surface plasmon resonance experiments. H.-S. C. and J. Y. K. contributed to data analysis. J. K., S. H. N. and M. G. L. planned the study, contributed to analysis of the data and wrote the paper. All authors discussed the results and commented on the manuscript. The authors declare no competing financial interests. Publisher Copyright: {\textcopyright} 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd",

year = "2016",

month = jul,

day = "1",

doi = "10.1111/tra.12403",

language = "English",

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T1 - Monomerization and ER Relocalization of GRASP Is a Requisite for Unconventional Secretion of CFTR

AU - Kim, Jiyoon

AU - Noh, Shin Hye

AU - Piao, He

AU - Kim, Dong Hee

AU - Kim, Kuglae

AU - Cha, Jeong Seok

AU - Chung, Woo Young

AU - Cho, Hyun Soo

AU - Kim, Joo Young

AU - Lee, Min Goo

N1 - Funding Information: We thank Dong Soo Chang for the assistance with illustrations and the Yonsei-Carl Zeiss Advanced Imaging Center for technical assistance. This work was supported by grants 2013R1A3A2042197 and 2007–0056092 from the National Research Foundation, the Ministry of Science, ICT & Future Planning, Republic of Korea. J. K., S. H. N., H. P., D. H. K. and W. Y. C. performed molecular and immunofluorescence experiments and analyzed the data. J. S. C. and K. K. performed the surface plasmon resonance experiments. H.-S. C. and J. Y. K. contributed to data analysis. J. K., S. H. N. and M. G. L. planned the study, contributed to analysis of the data and wrote the paper. All authors discussed the results and commented on the manuscript. The authors declare no competing financial interests. Publisher Copyright: © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

PY - 2016/7/1

Y1 - 2016/7/1

N2 - Induction of endoplasmic reticulum (ER)-to-Golgi blockade or ER stress induces Golgi reassembly stacking protein (GRASP)-mediated, Golgi-independent unconventional cell-surface trafficking of the folding-deficient ΔF508-cystic fibrosis transmembrane conductance regulator (CFTR). However, molecular mechanisms underlying this process remain elusive. Here, we show that phosphorylation-dependent dissociation of GRASP homotypic complexes and subsequent relocalization of GRASP to the ER play a critical role in the unconventional secretion of CFTR. Immunolocalization analyses of mammalian cells revealed that the Golgi protein GRASP55 was redistributed to the ER by stimuli that induce unconventional secretion of ΔF508-CFTR, such as induction of ER-to-Golgi blockade by the Arf1 mutant. Notably, the same stimuli also induced phosphorylation of regions near the C-terminus of GRASP55 and dissociation of GRASP homomultimer complexes. Furthermore, phosphorylation-mimicking mutations of GRASP55 induced the monomerization and ER relocalization of GRASP55, and these changes were nullified by phosphorylation-inhibiting mutations. These results provide mechanistic insights into how GRASP accesses the ER-retained ΔF508-CFTR and mediates the ER stress-induced unconventional secretion pathway.

AB - Induction of endoplasmic reticulum (ER)-to-Golgi blockade or ER stress induces Golgi reassembly stacking protein (GRASP)-mediated, Golgi-independent unconventional cell-surface trafficking of the folding-deficient ΔF508-cystic fibrosis transmembrane conductance regulator (CFTR). However, molecular mechanisms underlying this process remain elusive. Here, we show that phosphorylation-dependent dissociation of GRASP homotypic complexes and subsequent relocalization of GRASP to the ER play a critical role in the unconventional secretion of CFTR. Immunolocalization analyses of mammalian cells revealed that the Golgi protein GRASP55 was redistributed to the ER by stimuli that induce unconventional secretion of ΔF508-CFTR, such as induction of ER-to-Golgi blockade by the Arf1 mutant. Notably, the same stimuli also induced phosphorylation of regions near the C-terminus of GRASP55 and dissociation of GRASP homomultimer complexes. Furthermore, phosphorylation-mimicking mutations of GRASP55 induced the monomerization and ER relocalization of GRASP55, and these changes were nullified by phosphorylation-inhibiting mutations. These results provide mechanistic insights into how GRASP accesses the ER-retained ΔF508-CFTR and mediates the ER stress-induced unconventional secretion pathway.

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ER -

Monomerization and ER Relocalization of GRASP Is a Requisite for Unconventional Secretion of CFTR

Abstract

Bibliographical note

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