Open AccessThe expression of prosaposin and its receptors, GRP37 and GPR37L1, are increased in the developing dorsal root ganglion
Author(s) -
Miho Taniguchi,
Hiroaki Nabeka,
Kimiko Yamamiya,
Md. Sakirul Islam Khan,
Tetsuya Shimokawa,
Farzana Islam,
Takuya Doihara,
Hiroyuki Wakisaka,
Naoto Kobayashi,
Fumihiko Hamada,
Seiji Matsuda
Publication year - 2021
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0255958
Subject(s) - receptor , microbiology and biotechnology , dorsal root ganglion , cytoplasm , biology , g protein coupled receptor , chemistry , biochemistry , anatomy , dorsum
Prosaposin (PSAP), a highly conserved glycoprotein, is a precursor of saposins A–D. Accumulating evidence suggests that PSAP is a neurotrophic factor, as well as a regulator of lysosomal enzymes. Recently, the orphan G-protein-coupled receptors GPR37 and GPR37L1 were recognized as PSAP receptors, but their functions have not yet been clarified. In this study, we examined the distribution of PSAP and its receptors in the dorsal root ganglion (DRG) during development using specific antibodies, and showed that PSAP accumulates primarily in lysosomes and is dispersed throughout the cytoplasm of satellite cells. Later, PSAP colocalized with two receptors in satellite cells, and formed a characteristic ring shape approximately 8 weeks after birth, during a period of rapid DRG development. This ring shape, which was only observed around larger neurons, is evidence that several satellite cells are synchronously activated. We found that sortilin, a transporter of a wide variety of intracellular proteins containing PSAP, is strongly localized to the inner side of satellite cells, which contact the neuronal surface. These findings suggest that PSAP and GPR37/GPR37L1 play a role in activating both satellite and nerve cells.