Abstract:
:During lactation, mammary epithelial cells secrete huge amounts of milk from their apical side. The current view is that caseins are secreted by exocytosis, whereas milk fat globules are released by budding, enwrapped by the plasma membrane. Owing to the number and large size of milk fat globules, the membrane surface needed for their release might exceed that of the apical plasma membrane. A large-scale proteomics analysis of both cytoplasmic lipid droplets and secreted milk fat globule membranes was used to decipher the cellular origins of the milk fat globule membrane. Surprisingly, differential analysis of protein profiles of these two organelles strongly suggest that, in addition to the plasma membrane, the endoplasmic reticulum and the secretory vesicles contribute to the milk fat globule membrane. Analysis of membrane-associated and raft microdomain proteins reinforces this possibility and also points to a role for lipid rafts in milk product secretion. Our results provide evidence for a significant contribution of the endoplasmic reticulum to the milk fat globule membrane and a role for SNAREs in membrane dynamics during milk secretion. These novel aspects point to a more complex model for milk secretion than currently envisioned.
journal_name
Mol Biol Celljournal_title
Molecular biology of the cellauthors
Honvo-Houéto E,Henry C,Chat S,Layani S,Truchet Sdoi
10.1091/mbc.E16-06-0364subject
Has Abstractpub_date
2016-10-01 00:00:00pages
2946-64issue
19eissn
1059-1524issn
1939-4586pii
mbc.E16-06-0364journal_volume
27pub_type
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