PHD3 inhibits cell proliferation through hydroxylation of PAX2 at proline 9

The oncoprotein transcription factor paired box 2 (PAX2) is aberrantly expressed in cancers, but the underlying mechanism remains elusive. Prolyl hydroxylase 3 (PHD3) hydroxylates the proline residue of HIFα, mediating HIFα degradation. The von Hippel-Lindau protein (pVHL) is an E3 ligase which med...

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Main Authors: Lun Jie, Wang Yuxin, Gao Qiang, Wang Yu, Zhang Hongwei, Fang Jing
Format: Article
Language:English
Published: China Science Publishing & Media Ltd. 2022-04-01
Series:Acta Biochimica et Biophysica Sinica
Subjects:
Online Access:https://www.sciengine.com/doi/10.3724/abbs.2022043
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author Lun Jie
Wang Yuxin
Gao Qiang
Wang Yu
Zhang Hongwei
Fang Jing
author_facet Lun Jie
Wang Yuxin
Gao Qiang
Wang Yu
Zhang Hongwei
Fang Jing
author_sort Lun Jie
collection DOAJ
description The oncoprotein transcription factor paired box 2 (PAX2) is aberrantly expressed in cancers, but the underlying mechanism remains elusive. Prolyl hydroxylase 3 (PHD3) hydroxylates the proline residue of HIFα, mediating HIFα degradation. The von Hippel-Lindau protein (pVHL) is an E3 ligase which mediates ubiquitination and degradation of hydroxylated HIFα. PHD3 and pVHL are found to inhibit the expression of PAX2, however, the molecular mechanism is unclear. Here we demonstrate that PHD3 hydroxylates PAX2 at proline 9, which is required for pVHL to mediate PAX2 ubiquitination and degradation. Overexpression of PHD3 enhances prolyl hydroxylation, ubiquitination and degradation of PAX2 with little effect on those of PAX2(P9A). PHD3 does not influence PAX2 expression in VHL-null cells. pVHL binds to PAX2 and enhances PAX2 ubiquitination and degradation. However, pVHL does not bind with PAX2(P9A) and cannot enhance its ubiquitination and degradation. Our results suggest that proline 9 hydroxylation is a prerequisite for PAX2 degradation by pVHL. Functional studies indicate that introduction of PAX2 into PAX2-null COS-7 cells promotes cell proliferation, which is suppressed by co-expression of PHD3 but not by hydroxylase-deficient PHD3(H196A). PHD3 inhibits PAX2-induced, but not PAX2(P9A)-induced proliferation of COS-7 cells. These results suggest that PHD3 hydroxylates PAX2, followed by pVHL-mediated PAX2 ubiquitination and degradation. This study also suggests that PHD3 inhibits cell proliferation through downregulating PAX2.
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spelling doaj.art-112e9c1098cb44daa9c6dce6125ed1272023-11-07T00:58:09ZengChina Science Publishing & Media Ltd.Acta Biochimica et Biophysica Sinica1672-91452022-04-015470871510.3724/abbs.202204320d259ccPHD3 inhibits cell proliferation through hydroxylation of PAX2 at proline 9Lun Jie0Wang Yuxin1Gao Qiang2Wang Yu3Zhang Hongwei4Fang Jing5["Cancer Institute, the Affiliated Hospital of Qingdao University, School of Basic Medicine of Qingdao University, Qingdao 266061, China"]["Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, Shanghai 200031, China"]["Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, Shanghai 200031, China"]["Cancer Institute, the Affiliated Hospital of Qingdao University, School of Basic Medicine of Qingdao University, Qingdao 266061, China"]["Shandong Provincial Maternal and Child Health Care Hospital, Jinan 250014, China"]["Cancer Institute, the Affiliated Hospital of Qingdao University, School of Basic Medicine of Qingdao University, Qingdao 266061, China"]The oncoprotein transcription factor paired box 2 (PAX2) is aberrantly expressed in cancers, but the underlying mechanism remains elusive. Prolyl hydroxylase 3 (PHD3) hydroxylates the proline residue of HIFα, mediating HIFα degradation. The von Hippel-Lindau protein (pVHL) is an E3 ligase which mediates ubiquitination and degradation of hydroxylated HIFα. PHD3 and pVHL are found to inhibit the expression of PAX2, however, the molecular mechanism is unclear. Here we demonstrate that PHD3 hydroxylates PAX2 at proline 9, which is required for pVHL to mediate PAX2 ubiquitination and degradation. Overexpression of PHD3 enhances prolyl hydroxylation, ubiquitination and degradation of PAX2 with little effect on those of PAX2(P9A). PHD3 does not influence PAX2 expression in VHL-null cells. pVHL binds to PAX2 and enhances PAX2 ubiquitination and degradation. However, pVHL does not bind with PAX2(P9A) and cannot enhance its ubiquitination and degradation. Our results suggest that proline 9 hydroxylation is a prerequisite for PAX2 degradation by pVHL. Functional studies indicate that introduction of PAX2 into PAX2-null COS-7 cells promotes cell proliferation, which is suppressed by co-expression of PHD3 but not by hydroxylase-deficient PHD3(H196A). PHD3 inhibits PAX2-induced, but not PAX2(P9A)-induced proliferation of COS-7 cells. These results suggest that PHD3 hydroxylates PAX2, followed by pVHL-mediated PAX2 ubiquitination and degradation. This study also suggests that PHD3 inhibits cell proliferation through downregulating PAX2.https://www.sciengine.com/doi/10.3724/abbs.2022043PHD3PAX2pVHLprolyl hydroxylationcell proliferation
spellingShingle Lun Jie
Wang Yuxin
Gao Qiang
Wang Yu
Zhang Hongwei
Fang Jing
PHD3 inhibits cell proliferation through hydroxylation of PAX2 at proline 9
Acta Biochimica et Biophysica Sinica
PHD3
PAX2
pVHL
prolyl hydroxylation
cell proliferation
title PHD3 inhibits cell proliferation through hydroxylation of PAX2 at proline 9
title_full PHD3 inhibits cell proliferation through hydroxylation of PAX2 at proline 9
title_fullStr PHD3 inhibits cell proliferation through hydroxylation of PAX2 at proline 9
title_full_unstemmed PHD3 inhibits cell proliferation through hydroxylation of PAX2 at proline 9
title_short PHD3 inhibits cell proliferation through hydroxylation of PAX2 at proline 9
title_sort phd3 inhibits cell proliferation through hydroxylation of pax2 at proline 9
topic PHD3
PAX2
pVHL
prolyl hydroxylation
cell proliferation
url https://www.sciengine.com/doi/10.3724/abbs.2022043
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AT wangyuxin phd3inhibitscellproliferationthroughhydroxylationofpax2atproline9
AT gaoqiang phd3inhibitscellproliferationthroughhydroxylationofpax2atproline9
AT wangyu phd3inhibitscellproliferationthroughhydroxylationofpax2atproline9
AT zhanghongwei phd3inhibitscellproliferationthroughhydroxylationofpax2atproline9
AT fangjing phd3inhibitscellproliferationthroughhydroxylationofpax2atproline9