Related Experiment Video
Updated: Jun 10, 2026

Luciferase Complementation Imaging Assay in Nicotiana benthamiana Leaves for Transiently Determining Protein-protein Interaction Dynamics
Published on: November 20, 2017
A dynamic cpSRP43-Albino3 interaction mediates translocase regulation of chloroplast signal recognition particle
Nathaniel E Lewis1, Naomi J Marty, Karuppanan Muthusamy Kathir
1Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas 72701, USA.
Abstract:
The chloroplast signal recognition particle (cpSRP) and its receptor, chloroplast FtsY (cpFtsY), form an essential complex with the translocase Albino3 (Alb3) during post-translational targeting of light-harvesting chlorophyll-binding proteins (LHCPs). Here, we describe a combination of studies that explore the binding interface and functional role of a previously identified cpSRP43-Alb3 interaction. Using recombinant proteins corresponding to the C terminus of Alb3 (Alb3-Cterm) and various domains of cpSRP43, we identify the ankyrin repeat region of cpSRP43 as the domain primarily responsible for the interaction with Alb3-Cterm. Furthermore, we show Alb3-Cterm dissociates a cpSRP·LHCP targeting complex in vitro and stimulates GTP hydrolysis by cpSRP54 and cpFtsY in a strictly cpSRP43-dependent manner. These results support a model in which interactions between the ankyrin region of cpSRP43 and the C terminus of Alb3 promote distinct membrane-localized events, including LHCP release from cpSRP and release of targeting components from Alb3.
More Related Videos
11:10Protein-protein Interactions Visualized by Bimolecular Fluorescence Complementation in Tobacco Protoplasts and Leaves
Published on: March 9, 2014
08:04A New Approach for the Comparative Analysis of Multiprotein Complexes Based on 15N Metabolic Labeling and Quantitative Mass Spectrometry
Published on: March 13, 2014
Related Concept Videos
Protein Transport to the Inner Chloroplast Membrane
Protein Transport to the Thylakoids
Protein Transport to the Outer Chloroplast Membrane
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.
Protein Transport to the Stroma
Protein complexes called the translocon of the outer chloroplast membrane or TOC complex, and the translocon of the inner chloroplast membrane or TIC complex mediate the...
Regulation of Nuclear Protein Sorting
Cotranslational Protein Translocation
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...