Elongation factor MdEF‐Tu coordinates with heat shock protein MdHsp70 to enhance apple thermotolerance

Citations Over TimeTop 24% of 2023 papers

Abstract

High-temperature stress results in protein misfolding/unfolding and subsequently promotes the accumulation of cytotoxic protein aggregates that can compromise cell survival. Heat shock proteins (HSPs) function as molecular chaperones that coordinate the refolding and degradation of aggregated proteins to mitigate the detrimental effects of high temperatures. However, the relationship between HSPs and protein aggregates in apples under high temperatures remains unclear. Here, we show that an apple (Malus domestica) chloroplast-localized, heat-sensitive elongation factor Tu (MdEF-Tu), positively regulates apple thermotolerance when it is overexpressed. Transgenic apple plants exhibited higher photosynthetic capacity and better integrity of chloroplasts during heat stress. Under high temperatures, MdEF-Tu formed insoluble aggregates accompanied by ubiquitination modifications. Furthermore, we identified a chaperone heat shock protein (MdHsp70), as an interacting protein of MdEF-Tu. Moreover, we observed obviously elevated MdHsp70 levels in 35S: MdEF-Tu apple plants that prevented the accumulation of ubiquitinated MdEF-Tu aggregates, which positively contributes to the thermotolerance of the transgenic plants. Overall, our results provide new insights into the molecular chaperone function of MdHsp70, which mediates the homeostasis of thermosensitive proteins under high temperatures.

Related Papers

• → The HSP90 chaperone machinery(2017)1,503 cited
• → Bacterial proteostasis balances energy and chaperone utilization efficiently(2017)71 cited
• → Cellular Protein Aggregates: Formation, Biological Effects, and Ways of Elimination(2023)69 cited
• → The Role of Hsp90 in Retinal Proteostasis and Disease(2022)7 cited
• → Quantifying Chaperone-Mediated Transitions in the Proteostasis Network of E. coli(2013)6 cited