Identification of human SEP1 as a glial cell line-derived neurotrophic factor-inducible protein and its expression in the nervous system

• Published in: Neuroscience Vol. 121; no. 4; pp. 899 - 906
• Main Authors: Shimoyama, Y, Morikawa, Y, Ichihara, M, Kodama, Y, Fukuda, N, Hayashi, H, Morinaga, T, Iwashita, T, Murakumo, Y, Takahashi, M
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.01.2003; Elsevier
• Subjects: Animals; Antibodies - pharmacology; Biological and medical sciences; Cell Line; DNA, Complementary - genetics; DNA, Complementary - isolation & purification; dorsal root ganglia; Exoribonucleases - biosynthesis; Exoribonucleases - genetics; Exoribonucleases - isolation & purification; Fluorescent Antibody Technique; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation - drug effects; Gene Expression Regulation - genetics; General aspects. Models. Methods; Glial Cell Line-Derived Neurotrophic Factor; Glial Cell Line-Derived Neurotrophic Factor Receptors; Humans; Immunohistochemistry; immunostaining; Mice; Mice, Inbred C57BL; Microtubule-Associated Proteins - biosynthesis; Microtubule-Associated Proteins - genetics; Microtubule-Associated Proteins - isolation & purification; Microtubules - drug effects; Microtubules - metabolism; Molecular Sequence Data; Nerve Growth Factors - metabolism; Nerve Growth Factors - pharmacology; Nervous System - drug effects; Nervous System - metabolism; Neuroblastoma; neuronal differentiation; Neurons - cytology; Neurons - metabolism; Organ Specificity; Proto-Oncogene Proteins - genetics; Proto-Oncogene Proteins - metabolism; Proto-Oncogene Proteins c-ret; Receptor Protein-Tyrosine Kinases - genetics; Receptor Protein-Tyrosine Kinases - metabolism; RET tyrosine kinase; Saccharomyces cerevisiae Proteins - genetics; superior cervical ganglia; Tubulin - metabolism; Vertebrates: nervous system and sense organs; PBS; SDS; RET tyrosine kinase; PSPN; dorsal root ganglia; immunostaining; PFA; neuronal differentiation; FITC; GDNF; superior cervical ganglia; ARTN; PMSF; RT-PCR; NRTN; GAPDH; GFRα; Human; Spinal cord; Central nervous system; Superior cervical ganglion; Sympathetic nervous system; Gene expression; Neurotrophic factor; Autonomic nervous system; Glial cell line derived neurotrophic factor; Spinal ganglion
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/S0306-4522(03)00487-1

Glial cell line-derived neurotrophic factor (GDNF) signals through multisubunit receptor complex consisting of RET tyrosine kinase and a glycosylphosphatidylinositol-anchored coreceptor called GDNF family receptor α1 (GFRα1). In the current study, we cloned a human SEP1 gene as a GDNF-inducible gene using human neuroblastoma cells that express RET and GFRα1. The induction of the SEP1 gene showed two peaks at 0.5–2 h and 24–48 h after GDNF stimulation by Northern blotting and quantitative real-time reverse transcriptase polymerase chain reaction. The late induction was also confirmed at protein levels by Western blotting with anti-SEP1 antibody. Immunostaining revealed that the expression of the SEP1 protein was detected in cell body, elongated neurites and growth cone-like structure of neuroblastoma cells treated with GDNF. In addition, we found a high level of SEP1 expression in neurons of the dorsal root and superior cervical ganglia and motor neurons of the spinal cord of mice in which RET is also expressed. SEP1 was co-immunoprecipitated with α- and β-tubulins from the lysate of mouse brain. These results thus suggested that SEP1 is a GDNF-inducible and microtubule-associated protein that may play a role in the nervous system.