Avian eggshell formation reveals a new paradigm for vertebrate mineralization via vesicular amorphous calcium carbonate
Metadatos
Afficher la notice complèteEditorial
Amer Soc Biochemistry Molecular Biology Inc
Date
2020-11-20Referencia bibliográfica
Stapane, L., Le Roy, N., Ezagal, J., Rodriguez-Navarro, A. B., Labas, V., Combes-Soia, L., ... & Gautron, J. (2020). Avian eggshell formation reveals a new paradigm for vertebrate mineralization via vesicular amorphous calcium carbonate. Journal of Biological Chemistry, 295(47), 15853-15869. [DOI 10.1074/jbc.RA120.014542]
Patrocinador
Universite Francois Rabelais de Tours; Region Centre-Val de Loire; Natural Sciences and Engineering Research Council of Canada RGPIN-2016-04410; Le STUDIUMRésumé
Amorphous calcium carbonate (ACC) is an unstable mineral
phase, which is progressively transformed into aragonite or calcite
in biomineralization of marine invertebrate shells or avian
eggshells, respectively. We have previously proposed a model of
vesicular transport to provide stabilized ACC in chicken uterine
fluid where eggshell mineralization takes place. Herein, we
report further experimental support for this model. We confirmed
the presence of extracellular vesicles (EVs) using transmission
EM and showed high levels of mRNA of vesicular
markers in the oviduct segments where eggshell mineralization
occurs. We also demonstrate that EVs contain ACC in uterine
fluid using spectroscopic analysis. Moreover, proteomics and
immunofluorescence confirmed the presence of major vesicular,
mineralization-specific and eggshell matrix proteins in the
uterus and in purified EVs. We propose a comprehensive role
for EVs in eggshell mineralization, in which annexins transfer
calcium into vesicles and carbonic anhydrase 4 catalyzes the formation
of bicarbonate ions (HCO23
), for accumulation of ACC
in vesicles. We hypothesize that ACC is stabilized by ovalbumin
and/or lysozyme or additional vesicle proteins identified in this
study. Finally, EDIL3 and MFGE8 are proposed to serve as guidance
molecules to target EVs to the mineralization site. We
therefore report for the first-time experimental evidence for the
components of vesicular transport to supply ACC in a vertebrate
model of biomineralization.