Non-muscle myosin II drives vesicle loss during human reticulocyte maturation
Pedro L. Moura,
Bethan R. Hawley,
Tosti J. Mankelow,
Rebecca E. Griffiths,
Johannes G.G. Dobbe,
Geert J. Streekstra,
David J. Anstee,
Timothy J. Satchwell,
Ashley M. Toye
Affiliations
Pedro L. Moura
School of Biochemistry, University of Bristol, UK
Bethan R. Hawley
School of Biochemistry, University of Bristol, UK
Tosti J. Mankelow
Bristol Institute for Transfusion Sciences, National Health Service Blood and Transplant (NHSBT), UK;NIHR Blood and Transplant Research Unit, University of Bristol, UK
Rebecca E. Griffiths
Bristol Institute for Transfusion Sciences, National Health Service Blood and Transplant (NHSBT), UK;NIHR Blood and Transplant Research Unit, University of Bristol, UK;UQ-StemCARE, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Australia
Johannes G.G. Dobbe
Department of Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, the Netherlands
Geert J. Streekstra
Department of Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, the Netherlands
David J. Anstee
Bristol Institute for Transfusion Sciences, National Health Service Blood and Transplant (NHSBT), UK;NIHR Blood and Transplant Research Unit, University of Bristol, UK
Timothy J. Satchwell
School of Biochemistry, University of Bristol, UK;Bristol Institute for Transfusion Sciences, National Health Service Blood and Transplant (NHSBT), UK;NIHR Blood and Transplant Research Unit, University of Bristol, UK
Ashley M. Toye
School of Biochemistry, University of Bristol, UK;Bristol Institute for Transfusion Sciences, National Health Service Blood and Transplant (NHSBT), UK;NIHR Blood and Transplant Research Unit, University of Bristol, UK
The process of maturation of reticulocytes into fully mature erythrocytes that occurs in the circulation is known to be characterized by a complex interplay between loss of cell surface area and volume, removal of remnant cell organelles and redundant proteins, and highly selective membrane and cytoskeletal remodeling. However, the mechanisms that underlie and drive these maturational processes in vivo are currently poorly understood and, at present, reticulocytes derived through in vitro culture fail to undergo the final transition to erythrocytes. Here, we used high-throughput proteomic methods to highlight differences between erythrocytes, cultured reticulocytes and endogenous reticulocytes. We identify a cytoskeletal protein, non-muscle myosin IIA (NMIIA) whose abundance and phosphorylation status differs between reticulocytes and erythrocytes and localized it in the proximity of autophagosomal vesicles. An ex vivo circulation system was developed to simulate the mechanical shear component of circulation and demonstrated that mechanical stimulus is necessary, but insufficient for reticulocyte maturation. Using this system in concurrence with non-muscle myosin II inhibition, we demonstrate the involvement of non-muscle myosin IIA in reticulocyte remodeling and propose a previously undescribed mechanism of shear stress-responsive vesicle clearance that is crucial for reticulocyte maturation.
