RPGR protein complex regulates proteasome activity and mediates store-operated calcium entry

Sarita Rani Patnaik, Xun Zhang, Lincoln Biswas, Saeed Akhtar, Xinzhi Zhou, Deva Krupakar Kusuluri, James Reilly, Helen May-Simera, Susan Chalmers, John G. McCarron, Xinhua Shu

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Ciliopathies are a group of genetically heterogeneous disorders, characterized by defects in cilia genesis or maintenance. Mutations in the RPGR gene and its interacting partners, RPGRIP1 and RPGRIP1L, cause ciliopathies, but the function of their proteins remains unclear. Here we show that knockdown (KD) of RPGR, RPGRIP1 or RPGRIP1L in hTERT-RPE1 cells results in abnormal actin cytoskeleton organization. The actin cytoskeleton rearrangement is regulated by the small GTPase RhoA via the planar cell polarity (PCP) pathway. RhoA activity was upregulated in the absence of RPGR, RPGRIP1 or RPGRIP1L proteins. In RPGR, RPGRIP1 or RPGRIP1L KD cells, we observed increased levels of DVl2 and DVl3 proteins, the core components of the PCP pathway, due to impaired proteasomal activity. RPGR, RPGRIP1 or RPGRIP1L KD cells treated with thapsigargin (TG), an inhibitor of sarcoendoplasmic reticulum Ca2+ - ATPases, showed impaired store-operated Ca2+ entry (SOCE), which is mediated by STIM1 and Orai1 proteins. STIM1 was not localized to the ER-PM junction upon ER store depletion in RPGR, RPGRIP1 or RPGRIP1L KD cells. Our results demonstrate that the RPGR protein complex is required for regulating proteasomal activity and for modulating SOCE, which may contribute to the ciliopathy phenotype.
LanguageEnglish
Pages23183-23197
Number of pages15
JournalOncotarget
Volume9
Issue number33
DOIs
Publication statusPublished - 1 May 2018

Fingerprint

Proteasome Endopeptidase Complex
Calcium
Cell Polarity
Actin Cytoskeleton
Proteins
Reticulum
Thapsigargin
Monomeric GTP-Binding Proteins
Calcium-Transporting ATPases
Cilia
Maintenance
Phenotype
Mutation
Genes
Ciliopathies

Keywords

  • ciliopathy
  • RPGR complex
  • actin cytoskeleton
  • endoplasmic reticulum
  • store-operated Ca2+ entry

Cite this

Patnaik, S. R., Zhang, X., Biswas, L., Akhtar, S., Zhou, X., Kusuluri, D. K., ... Shu, X. (2018). RPGR protein complex regulates proteasome activity and mediates store-operated calcium entry. Oncotarget, 9(33), 23183-23197. https://doi.org/10.18632/oncotarget.25259
Patnaik, Sarita Rani ; Zhang, Xun ; Biswas, Lincoln ; Akhtar, Saeed ; Zhou, Xinzhi ; Kusuluri, Deva Krupakar ; Reilly, James ; May-Simera, Helen ; Chalmers, Susan ; McCarron, John G. ; Shu, Xinhua. / RPGR protein complex regulates proteasome activity and mediates store-operated calcium entry. In: Oncotarget. 2018 ; Vol. 9, No. 33. pp. 23183-23197.
@article{d585ac9b4ca04d8fa0a28e7ff9f2adbd,
title = "RPGR protein complex regulates proteasome activity and mediates store-operated calcium entry",
abstract = "Ciliopathies are a group of genetically heterogeneous disorders, characterized by defects in cilia genesis or maintenance. Mutations in the RPGR gene and its interacting partners, RPGRIP1 and RPGRIP1L, cause ciliopathies, but the function of their proteins remains unclear. Here we show that knockdown (KD) of RPGR, RPGRIP1 or RPGRIP1L in hTERT-RPE1 cells results in abnormal actin cytoskeleton organization. The actin cytoskeleton rearrangement is regulated by the small GTPase RhoA via the planar cell polarity (PCP) pathway. RhoA activity was upregulated in the absence of RPGR, RPGRIP1 or RPGRIP1L proteins. In RPGR, RPGRIP1 or RPGRIP1L KD cells, we observed increased levels of DVl2 and DVl3 proteins, the core components of the PCP pathway, due to impaired proteasomal activity. RPGR, RPGRIP1 or RPGRIP1L KD cells treated with thapsigargin (TG), an inhibitor of sarcoendoplasmic reticulum Ca2+ - ATPases, showed impaired store-operated Ca2+ entry (SOCE), which is mediated by STIM1 and Orai1 proteins. STIM1 was not localized to the ER-PM junction upon ER store depletion in RPGR, RPGRIP1 or RPGRIP1L KD cells. Our results demonstrate that the RPGR protein complex is required for regulating proteasomal activity and for modulating SOCE, which may contribute to the ciliopathy phenotype.",
keywords = "ciliopathy, RPGR complex, actin cytoskeleton, endoplasmic reticulum, store-operated Ca2+ entry",
author = "Patnaik, {Sarita Rani} and Xun Zhang and Lincoln Biswas and Saeed Akhtar and Xinzhi Zhou and Kusuluri, {Deva Krupakar} and James Reilly and Helen May-Simera and Susan Chalmers and McCarron, {John G.} and Xinhua Shu",
year = "2018",
month = "5",
day = "1",
doi = "10.18632/oncotarget.25259",
language = "English",
volume = "9",
pages = "23183--23197",
journal = "Oncotarget",
issn = "1949-2553",
number = "33",

}

Patnaik, SR, Zhang, X, Biswas, L, Akhtar, S, Zhou, X, Kusuluri, DK, Reilly, J, May-Simera, H, Chalmers, S, McCarron, JG & Shu, X 2018, 'RPGR protein complex regulates proteasome activity and mediates store-operated calcium entry' Oncotarget, vol. 9, no. 33, pp. 23183-23197. https://doi.org/10.18632/oncotarget.25259

RPGR protein complex regulates proteasome activity and mediates store-operated calcium entry. / Patnaik, Sarita Rani; Zhang, Xun; Biswas, Lincoln; Akhtar, Saeed; Zhou, Xinzhi; Kusuluri, Deva Krupakar; Reilly, James; May-Simera, Helen; Chalmers, Susan; McCarron, John G.; Shu, Xinhua.

In: Oncotarget, Vol. 9, No. 33, 01.05.2018, p. 23183-23197.

Research output: Contribution to journalArticle

TY - JOUR

T1 - RPGR protein complex regulates proteasome activity and mediates store-operated calcium entry

AU - Patnaik, Sarita Rani

AU - Zhang, Xun

AU - Biswas, Lincoln

AU - Akhtar, Saeed

AU - Zhou, Xinzhi

AU - Kusuluri, Deva Krupakar

AU - Reilly, James

AU - May-Simera, Helen

AU - Chalmers, Susan

AU - McCarron, John G.

AU - Shu, Xinhua

PY - 2018/5/1

Y1 - 2018/5/1

N2 - Ciliopathies are a group of genetically heterogeneous disorders, characterized by defects in cilia genesis or maintenance. Mutations in the RPGR gene and its interacting partners, RPGRIP1 and RPGRIP1L, cause ciliopathies, but the function of their proteins remains unclear. Here we show that knockdown (KD) of RPGR, RPGRIP1 or RPGRIP1L in hTERT-RPE1 cells results in abnormal actin cytoskeleton organization. The actin cytoskeleton rearrangement is regulated by the small GTPase RhoA via the planar cell polarity (PCP) pathway. RhoA activity was upregulated in the absence of RPGR, RPGRIP1 or RPGRIP1L proteins. In RPGR, RPGRIP1 or RPGRIP1L KD cells, we observed increased levels of DVl2 and DVl3 proteins, the core components of the PCP pathway, due to impaired proteasomal activity. RPGR, RPGRIP1 or RPGRIP1L KD cells treated with thapsigargin (TG), an inhibitor of sarcoendoplasmic reticulum Ca2+ - ATPases, showed impaired store-operated Ca2+ entry (SOCE), which is mediated by STIM1 and Orai1 proteins. STIM1 was not localized to the ER-PM junction upon ER store depletion in RPGR, RPGRIP1 or RPGRIP1L KD cells. Our results demonstrate that the RPGR protein complex is required for regulating proteasomal activity and for modulating SOCE, which may contribute to the ciliopathy phenotype.

AB - Ciliopathies are a group of genetically heterogeneous disorders, characterized by defects in cilia genesis or maintenance. Mutations in the RPGR gene and its interacting partners, RPGRIP1 and RPGRIP1L, cause ciliopathies, but the function of their proteins remains unclear. Here we show that knockdown (KD) of RPGR, RPGRIP1 or RPGRIP1L in hTERT-RPE1 cells results in abnormal actin cytoskeleton organization. The actin cytoskeleton rearrangement is regulated by the small GTPase RhoA via the planar cell polarity (PCP) pathway. RhoA activity was upregulated in the absence of RPGR, RPGRIP1 or RPGRIP1L proteins. In RPGR, RPGRIP1 or RPGRIP1L KD cells, we observed increased levels of DVl2 and DVl3 proteins, the core components of the PCP pathway, due to impaired proteasomal activity. RPGR, RPGRIP1 or RPGRIP1L KD cells treated with thapsigargin (TG), an inhibitor of sarcoendoplasmic reticulum Ca2+ - ATPases, showed impaired store-operated Ca2+ entry (SOCE), which is mediated by STIM1 and Orai1 proteins. STIM1 was not localized to the ER-PM junction upon ER store depletion in RPGR, RPGRIP1 or RPGRIP1L KD cells. Our results demonstrate that the RPGR protein complex is required for regulating proteasomal activity and for modulating SOCE, which may contribute to the ciliopathy phenotype.

KW - ciliopathy

KW - RPGR complex

KW - actin cytoskeleton

KW - endoplasmic reticulum

KW - store-operated Ca2+ entry

UR - http://www.oncotarget.com/

U2 - 10.18632/oncotarget.25259

DO - 10.18632/oncotarget.25259

M3 - Article

VL - 9

SP - 23183

EP - 23197

JO - Oncotarget

T2 - Oncotarget

JF - Oncotarget

SN - 1949-2553

IS - 33

ER -

Patnaik SR, Zhang X, Biswas L, Akhtar S, Zhou X, Kusuluri DK et al. RPGR protein complex regulates proteasome activity and mediates store-operated calcium entry. Oncotarget. 2018 May 1;9(33):23183-23197. https://doi.org/10.18632/oncotarget.25259