AtDeg2 – a chloroplast protein with dual protease/chaperone activity

Przemysław Jagodzik,Małgorzata Adamiec,Grzegorz Jackowski

doi:10.5586/asbp.2014.018

Przemysław Jagodzik, Małgorzata Adamiec + Show 1 more

Open Access

https://doi.org/10.5586/asbp.2014.018

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Abstract

Chloroplast protease AtDeg2 (an ATP-independent serine endopeptidase) is cytosolically synthesized as a precursor, which is imported into the chloroplast stroma and deprived of its transit peptide. Then the mature protein undergoes routing to its functional location at the stromal side of thylakoid membrane. In its linear structure AtDeg2 molecule contains the protease domain with catalytic triad (HDS) and two PDZ domains (PDZ1 and PDZ2). In vivo AtDeg2 most probably exists as a supposedly inactive haxamer, which may change its oligomeric stage to form active 12-mer, or 24-mer. AtDeg2 has recently been demonstrated to exhibit dual protease/chaperone function. This review is focused on the current awareness with regard to AtDeg2 structure and functional significance.

Highlights

The results of studies performed in recent years show that regulatory protein hydrolysis, catalyzed by proteolytic enzymes occurs ubiquitously and is directly or indirectly involved in a majority cellular processes of living organisms
Protein turnover involves a hydrolysis of proteins, which become unnecessary in a defined ontogenetical context under comfortable environmental conditions
All of them possess a conservative AAA+ domain which is responsible for ATP binding and hydrolysis, necessary to unfold protein substrates so that they can enter a catalytical chamber of the proteases molecule through a narrow entrance [1]

Summary

Introduction

The results of studies performed in recent years show that regulatory protein hydrolysis, catalyzed by proteolytic enzymes occurs ubiquitously and is directly or indirectly involved in a majority (if not all) cellular processes of living organisms. All of them possess a conservative AAA+ domain which is responsible for ATP binding and hydrolysis, necessary to unfold protein substrates so that they can enter a catalytical chamber of the proteases molecule through a narrow entrance [1].

Results

Conclusion