Unité mixte de recherche Science et technologie du lait et de l'œuf

Unité mixte de recherche Science et technologie du lait et de l'œuf

An in situ approach to illustrate the structure of milk casein micelle

Casein micelles play a key role in the textural and nutritional properties of dairy products. We present a new way to study their structure: investigate their in situ development in the secretory pathway of the mammary epithelial cell.

Although the subject of many papers for over 30 years, the organization of micelles as supramolecular complexes composed of caseines linked to colloidal calcium phosphate is only partially understood. Two INRA teams study, in situ, the mechanisms of development and transport of the casein micelle in the mammary epithelial cell.

  • This work demonstrates the existence of a membrane-associated form of αS1-casein in the endoplasmic reticulum and more distal compartments of the cell. The dimerization of αS1-casein via a disulfide bond increases this interaction.
  • αS1-casein is essential for the export of other caseins from the endoplasmic reticulum to the Golgi apparatus.

Caracterisation of micellar structure using permeabilisation of microsomes.

Caracterisation of micellar structure using permeabilisation of microsomes

Rough endoplasmic reticulum-derived microsomes were prepared from mammary tissues.


Ongoing studies consider micelle development during its traffic through the Golgi apparatus where caseins are subjected to various post-translational modifications such as phosphorylation and glycosylation.





Unité Génomique et Physiologie de la Lactation, INRA Jouy-en-Josas, France

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Le Parc A., Léonil J., Chanat E. (2010) Alpha-S1 -casein, which is essential for efficient ER-to-Golgi transport, is also present in a tightly membrane-associated form. BMC Cell Biology 11:65


Annabelle Le Parc, STLO Bioactivité & Nutrition, INRA Jouy-en-Josas, France

Joëlle Léonil, STLO Bioactivité & Nutrition, INRA Rennes, France


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Rédaction : STLO
Date de création : 12 Mai 2011
Mise à jour : 22 Octobre 2013