From Fuzziness to Clarity: Regulation of DRP5B Ring Dynamics at the Chloroplast Division Site.

Tianhu Sun

doi:10.1104/pp.20.00199

Abstract

Plant cells harbor a varying number of chloroplasts, and chloroplasts multiply by division to maintain the continuity of chloroplasts. Chloroplast division is performed by the constriction of two self-assembling GTPase rings in the middle of the chloroplast: the FtsZ ring on the stromal side and the

Highlights

Plant cells harbor a varying number of chloroplasts, and chloroplasts multiply by division to maintain the continuity of chloroplasts
It is thought to provide the constriction force needed for chloroplast division by assembling a ring structure around the outside of the chloroplast that results in chloroplast fission. In this issue of Plant Physiology, Sun et al (2020) demonstrate that the assembly and remodeling of the DYNAMINRELATED PROTEIN5B (DRP5B) ring are differentially regulated by the chloroplast OEM proteins PLASTID DIVISION1 (PDV1) and PDV2 (Fig. 1)
When performing FRAP analysis of GFP-DRP5B and GFP-DRP5B(T82D) in the drp5B-2 phot2-1 background, a slower recovery of GFP-DRP5B(T82D) was observed. All these results indicated that GTP hydrolysis activity is not necessary for DRP5B association and assembly at the chloroplast division site but might affect subunit exchange

Summary

Introduction

Plant cells harbor a varying number of chloroplasts, and chloroplasts multiply by division to maintain the continuity of chloroplasts. In this issue of Plant Physiology, Sun et al (2020) demonstrate that the assembly and remodeling of the DRP5B ring are differentially regulated by the chloroplast OEM proteins PDV1 and PDV2 (Fig. 1). Observing the dynamic regulation of DRP5B ring assembly during chloroplast division presents a number of challenges. The authors transformed the drp5B-1 mutant with a GFP-DRP5B fusion construct.

Results

Conclusion