Journal
DEVELOPMENTAL BIOLOGY
Volume 393, Issue 1, Pages 33-43Publisher
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.ydbio.2014.06.024
Keywords
Calumin; CCDC47; ERAD; Embryogenesis; ER stress; Secretory cells
Categories
Funding
- JSPS KAKENHI [22790288, 24790073]
- Nakajima Foundation
- Grants-in-Aid for Scientific Research [24790073, 22112005, 22790288] Funding Source: KAKEN
Ask authors/readers for more resources
Calumin is an endoplasmic reticulum (ER)-transmembrane protein, and little is known about its physiological roles. Here we showed that calumin homozygous mutant embryos die at embryonic days (E) 10.5-11.5. At mid-gestation, calumin was expressed predominantly in the yolk sac. Apoptosis was enhanced in calumin homozygous mutant yolk sacs at E9.5, pointing to a possible link to the embryonic lethality. Calumin co-immunoprecipitated with ERAD components such as p97, BIP, derlin-1, derlin-2 and VIMP, suggesting its involvement in ERAD. Indeed, calumin knockdown in HEK 293 cells resulted in ERAD being less efficient, as demonstrated by attenuation in both degradations of a misfolded alpha 1-antitrypsin variant and the ER-to-cytosol dislocation of cholera toxin A1 subunit. In calumin homozygous mutant yolk sac endoderm cells, ER stress-associated alterations were observed, including lipid droplet accumulation, fragmentation of the ER and dissociation of ribosomes from the ER. In this context, the ER-overload response, assumed to be cytoprotective, was also triggered in the mutant endoderm cells, but seemed to fully counteract the excessive ER stress generated due to defective ERAD. Taken together, our findings suggested that calumin serves to maintain the yolk sac integrity through participation in the ERAD activity, contributing to embryonic development. (C) 2014 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available