Multimodal imaging reveals membrane skeleton reorganisation during reticulocyte maturation and differences in dimple and rim regions of mature erythrocytes
Journal Title
Journal of Structural Biology X
Abstract
The red blood cell (RBC) is remarkable in its ability to deform as it passages through the vasculature. Its deformability derives from a spectrin-actin protein network that supports the cell membrane and provides strength and flexibility, however questions remain regarding the assembly and maintenance of the skeletal network. Using scanning electron microscopy (SEM) and atomic force microscopy (AFM) we have examined the nanoscale architecture of the cytoplasmic side of membrane discs prepared from reticulocytes and mature RBCs. Immunofluorescence microscopy was used to probe the distribution of spectrin and other membrane skeleton proteins. We found that the cell surface area decreases by up to 30% and the spectrin-actin network increases in density by approximately 20% as the reticulocyte matures. By contrast, the inter-junctional distance and junctional density increase only by 3-4% and 5-9%, respectively. This suggests that the maturation-associated reduction in surface area is accompanied by an increase in spectrin self-association to form higher order oligomers. We also examined the mature RBC membrane in the edge (rim) and face (dimple) regions of mature RBCs and found the rim contains about 1.5% more junctional complexes compared to the dimple region. A 2% increase in band 4.1 density in the rim supports these structural measurements.
Publisher
Elsevier
Keywords
Afm; Erythrocyte; Membrane skeleton; Reticulocyte; Sem; Shape memory
Research Division(s)
Infectious Diseases And Immune Defence
PubMed ID
34977554
Open Access at Publisher's Site
https://doi.org.10.1016/j.yjsbx.2021.100056
Terms of Use/Rights Notice
Refer to copyright notice on published article.


Creation Date: 2022-02-07 10:12:13
Last Modified: 2022-02-08 11:34:44
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