Open AccessArl8b is required for lysosomal degradation of maternal proteins in the visceral yolk sac endoderm of mouse embryos
Author(s) -
Miho Oka,
Keisuke Hashimoto,
Yoshifumi Yamaguchi,
Shin Ichiro Saitoh,
Yuki Sugiura,
Yuji Motoi,
Kurara Honda,
Yorifumi Kikko,
Shinya Ohata,
Makoto Suematsu,
Masayuki Miura,
Kensuke Miyake,
Toshiaki Katada,
Kenji Kontani
Publication year - 2017
Publication title -
journal of cell science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.384
H-Index - 278
eISSN - 1477-9137
pISSN - 0021-9533
DOI - 10.1242/jcs.200519
Subject(s) - biology , microbiology and biotechnology , embryo , lysosome , yolk sac , endocytic cycle , endoderm , embryogenesis , embryonic stem cell , biochemistry , endocytosis , cell , gene , enzyme
The small GTPase Arl8b localizes primarily to lysosomes and is involved in lysosomal motility and fusion. Here, we show that Arl8b is required for lysosomal degradation of maternal proteins in the visceral yolk sac endoderm (VYSE), an apical cell layer of the visceral yolk sac, of mouse embryos. The VYSE actively takes up maternal materials from uterine fluid and degrades them in lysosomes to provide breakdown products to the embryo as energy sources. Arl8b gene-trap mice (Arl8b−/−) displayed decreased early embryo body size. The Arl8b−/− VYSE exhibited defective endocytic trafficking to the lysosome and accumulation of maternal proteins such as albumin and immunoglobulin G in late endocytic organelles. Furthermore, Transthyretin-Cre;Arl8bflox/flox mice in which Arl8b was ablated specifically in the VYSE also showed decreased embryo body size, defects in trafficking to the lysosome, and reduction of the free amino acid level in the embryos. Taken together, these results suggest that Arl8b mediates lysosomal degradation of maternal proteins in the VYSE, thereby contributing to mouse embryonic development.