Identification of human SEP1 as a glial cell line-derived neurotrophic factor-inducible protein and its expression in the nervous system.
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 alpha1 (GFRalpha1). In the current study, we cloned a human SEP1 gene as a GDNF-inducible gene using human neuroblastoma cells that express RET and GFRalpha1. 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 alpha- and beta-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.
Shimoyama
Y
Y
Department of Pathology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
Morikawa
Y
Y
Ichihara
M
M
Kodama
Y
Y
Fukuda
N
N
Hayashi
H
H
Morinaga
T
T
Iwashita
T
T
Murakumo
Y
Y
Takahashi
M
M
D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002460:Cell Line; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D005095:Exoribonucleases / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000378:metabolism* / Q000494:pharmacology; D009420:Nervous System / Q000187:drug effects / Q000378:metabolism*; D009447:Neuroblastoma; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D009928:Organ Specificity; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics*; D014404:Tubulin / Q000378:metabolism
D000906:Antibodies; D018076:DNA, Complementary; C495039:GDNF protein, human; C494987:GFRA1 protein, human; C495040:Gdnf protein, mouse; C494988:Gfra1 protein, mouse; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D008869:Microtubule-Associated Proteins; D009414:Nerve Growth Factors; D011518:Proto-Oncogene Proteins; D029701:Saccharomyces cerevisiae Proteins; D014404:Tubulin; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C494999:Ret protein, mouse; D005095:Exoribonucleases; C068398:XRN1 protein, S cerevisiae; C470512:XRN1 protein, human