title: Expression and release of progalanin in fibroblasts.
abstract: Galanin is a neuropeptide expressed in the central and peripheral nervous systems. Galanin is known to be biosynthesized in neural and endocrine cells, but little evidence exists for its synthesis in other cells. In this study, we explored galanin-releasing nonneural cells using radioimmunoassay, finding that some fibroblasts produced and released the galanin-like immunoreactive component (galanin-LI). The molecular weight of the galanin-LI obtained from the fibroblasts, as measured by gel filtration chromatography and Western blotting, was 14 kDa and suggested that the compound was progalanin. Peptide mass fingerprinting analysis identified the large form of galanin-LI as progalanin without its signal sequence. In addition, galanin-LI was located in the Golgi bodies and vesicle-like structures of the fibroblasts. Furthermore, the addition of brefeldin A, an inhibitor of transport from the ER, decreased the release of galanin-LI. In this study, we showed that the fibroblast, a nonneural and nonendocrine cell type, produced and released a galanin precursor, progalanin, without processing via Golgi bodies or secretory vesicles.
authors.affiliation: Department of Microbiology and Molecular Cell Biology, Nihon Pharmaceutical University, 10281 Komuro, Ina-machi, Kitaadachi-gun, Saitama 362-0806, Japan; Laboratory of Bioorganic Chemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan. Electronic address: yamamoto@nichiyaku.ac.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamamoto
authors.affiliation: Laboratory of Bioorganic Chemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Iguchi
authors.affiliation: Laboratory of Bioorganic Chemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Unno
authors.affiliation: Laboratory of Cell and Molecular Biology of Aging, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Kaji
authors.affiliation: Laboratory of Bioorganic Chemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Hoshino
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002645:Chickens; D003412:Cricetulus; D005347:Fibroblasts / Q000378:metabolism*; D019004:Galanin / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D051379:Mice
chemical_list: D019004:Galanin
keywords: Galanin; MALDI-TOF mass spectrometry; Neuropeptide; Processing; Structural analysis