Inverse Correlation Between MPSR1 E3 Ubiquitin Ligase and HSP90.1 Balances Cytoplasmic Protein Quality Control

TY - JOUR

T1 - Inverse Correlation Between MPSR1 E3 Ubiquitin Ligase and HSP90.1 Balances Cytoplasmic Protein Quality Control

AU - Kim, Jong Hum

AU - Oh, Tae Rin

AU - Cho, Seok Keun

AU - Yang, Seong Wook

AU - Kim, Woo Taek

PY - 2019/6/1

Y1 - 2019/6/1

N2 - MISFOLDED PROTEIN SENSING RING1 (MPSR1) is a chaperone-independent E3 ubiquitin ligase that participates in protein quality control by eliminating misfolded proteins in Arabidopsis (Arabidopsis thaliana). Here, we report that in the early stages of proteotoxic stress, cellular levels of MPSR1 increased immediately, whereas levels of HEAT SHOCK PROTEIN90.1 (AtHSP90.1) were unaltered despite massively upregulated transcription. At this stage, the gene-silencing pathway mediated by microRNA 414 (miR414) suppressed AtHSP90.1 translation. By contrast, under prolonged stress, AtHSP90.1 was not suppressed, and instead competed with MPSR1 to act on misfolded proteins, promoting the destruction of MPSR1. Deficiency or excess of MPSR1 significantly abolished or intensified the suppression of AtHSP90.1, respectively. Similar to the MPSR1-overexpressing transgenic plants, the miR414-overexpressing plants showed an increased tolerance to proteotoxic stress as compared to the wild-type plants. Although the functional relationship between MPSR1 and miR414 remains unclear, both MPSR1 and miR414 demonstrated negative modulation of the expression of AtHSP90.1. The inverse correlation between MPSR1 and AtHSP90.1 via miR414 may adjust the setpoint of the HSP90-mediated protein quality control process in response to increasing stress intensity in Arabidopsis.

AB - MISFOLDED PROTEIN SENSING RING1 (MPSR1) is a chaperone-independent E3 ubiquitin ligase that participates in protein quality control by eliminating misfolded proteins in Arabidopsis (Arabidopsis thaliana). Here, we report that in the early stages of proteotoxic stress, cellular levels of MPSR1 increased immediately, whereas levels of HEAT SHOCK PROTEIN90.1 (AtHSP90.1) were unaltered despite massively upregulated transcription. At this stage, the gene-silencing pathway mediated by microRNA 414 (miR414) suppressed AtHSP90.1 translation. By contrast, under prolonged stress, AtHSP90.1 was not suppressed, and instead competed with MPSR1 to act on misfolded proteins, promoting the destruction of MPSR1. Deficiency or excess of MPSR1 significantly abolished or intensified the suppression of AtHSP90.1, respectively. Similar to the MPSR1-overexpressing transgenic plants, the miR414-overexpressing plants showed an increased tolerance to proteotoxic stress as compared to the wild-type plants. Although the functional relationship between MPSR1 and miR414 remains unclear, both MPSR1 and miR414 demonstrated negative modulation of the expression of AtHSP90.1. The inverse correlation between MPSR1 and AtHSP90.1 via miR414 may adjust the setpoint of the HSP90-mediated protein quality control process in response to increasing stress intensity in Arabidopsis.

UR - http://www.scopus.com/inward/record.url?scp=85067214386&partnerID=8YFLogxK

U2 - 10.1104/pp.18.01582

DO - 10.1104/pp.18.01582

M3 - Journal article

C2 - 30890661

AN - SCOPUS:85067214386

SN - 0032-0889

VL - 180

SP - 1230

EP - 1240

JO - Plant Physiology

JF - Plant Physiology

IS - 2

ER -