Skip to main content
NCBI home page
Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1994 Sep 27;91(20):9593–9596. doi: 10.1073/pnas.91.20.9593

Identification of prosaposin as a neurotrophic factor.

J S O'Brien 1, G S Carson 1, H C Seo 1, M Hiraiwa 1, Y Kishimoto 1
PMCID: PMC44859  PMID: 7937812

Abstract

Prosaposin was identified as a neurotrophic factor stimulating neurite outgrowth in murine neuroblastoma (NS20Y) cells and choline acetyltransferase (ChAT) activity in human neuroblastoma (SK-N-MC) cells. The four naturally occurring saposins, which are derived by proteolytic processing of prosaposin, were tested for activity. Saposin C was found to be active, whereas saposins A, B, and D were inactive as neurotrophic factors. Dose-response curves demonstrated that nanomolar concentrations of prosaposin and saposin C stimulated neurite outgrowth and increased ChAT activity. Prosaposin and saposin C exerted activity by a mechanism independent of nerve growth factor, brain-derived neurotrophic factor, and neurotrophin 3. Binding assays utilizing saposin C as a ligand gave two saturable binding constants, a high-affinity (Kd = 19 pM) and a low-affinity (Kd = 1 nM) constant, with 2000 and 15,000 sites per NS20Y cell, respectively. Phosphorylation stimulation experiments demonstrated that brief treatment with prosaposin or saposin C enhanced phosphorylation of a variety of proteins, some of which contained phosphorylated tyrosine(s). Since both cell lines were also stimulated by ciliary neurotrophic factor (CNTF) as well as prosaposin, inhibition was tested by utilizing an anti-gp130 monoclonal antibody, which specifically inhibited CNTF stimulation; this antibody did not inhibit prosaposin or saposin C stimulation. These results indicate that prosaposin and saposin C are neurotrophic factors which initiate signal transduction by binding to a high-affinity receptor that induces protein phosphorylation.

Full text

PDF
9593

Images in this article

9594Image
on p.9594
9595Image
on p.9595
9595Image
on p.9595

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Cooper J. A., Hunter T. Changes in protein phosphorylation in Rous sarcoma virus-transformed chicken embryo cells. Mol Cell Biol. 1981 Feb;1(2):165–178. doi: 10.1128/mcb.1.2.165. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Fonnum F. A rapid radiochemical method for the determination of choline acetyltransferase. J Neurochem. 1975 Feb;24(2):407–409. doi: 10.1111/j.1471-4159.1975.tb11895.x. [DOI] [PubMed] [Google Scholar]
  3. Greene L. A., Tischler A. S. Establishment of a noradrenergic clonal line of rat adrenal pheochromocytoma cells which respond to nerve growth factor. Proc Natl Acad Sci U S A. 1976 Jul;73(7):2424–2428. doi: 10.1073/pnas.73.7.2424. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Harzer K., Paton B. C., Poulos A., Kustermann-Kuhn B., Roggendorf W., Grisar T., Popp M. Sphingolipid activator protein deficiency in a 16-week-old atypical Gaucher disease patient and his fetal sibling: biochemical signs of combined sphingolipidoses. Eur J Pediatr. 1989 Oct;149(1):31–39. doi: 10.1007/BF02024331. [DOI] [PubMed] [Google Scholar]
  5. Hibi M., Murakami M., Saito M., Hirano T., Taga T., Kishimoto T. Molecular cloning and expression of an IL-6 signal transducer, gp130. Cell. 1990 Dec 21;63(6):1149–1157. doi: 10.1016/0092-8674(90)90411-7. [DOI] [PubMed] [Google Scholar]
  6. Hineno T., Sano A., Kondoh K., Ueno S., Kakimoto Y., Yoshida K. Secretion of sphingolipid hydrolase activator precursor, prosaposin. Biochem Biophys Res Commun. 1991 Apr 30;176(2):668–674. doi: 10.1016/s0006-291x(05)80236-0. [DOI] [PubMed] [Google Scholar]
  7. Hiraiwa M., O'Brien J. S., Kishimoto Y., Galdzicka M., Fluharty A. L., Ginns E. I., Martin B. M. Isolation, characterization, and proteolysis of human prosaposin, the precursor of saposins (sphingolipid activator proteins). Arch Biochem Biophys. 1993 Jul;304(1):110–116. doi: 10.1006/abbi.1993.1328. [DOI] [PubMed] [Google Scholar]
  8. Hiraiwa M., Soeda S., Kishimoto Y., O'Brien J. S. Binding and transport of gangliosides by prosaposin. Proc Natl Acad Sci U S A. 1992 Dec 1;89(23):11254–11258. doi: 10.1073/pnas.89.23.11254. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Kishimoto Y., Hiraiwa M., O'Brien J. S. Saposins: structure, function, distribution, and molecular genetics. J Lipid Res. 1992 Sep;33(9):1255–1267. [PubMed] [Google Scholar]
  10. Kondoh K., Hineno T., Sano A., Kakimoto Y. Isolation and characterization of prosaposin from human milk. Biochem Biophys Res Commun. 1991 Nov 27;181(1):286–292. doi: 10.1016/s0006-291x(05)81415-9. [DOI] [PubMed] [Google Scholar]
  11. Kondoh K., Sano A., Kakimoto Y., Matsuda S., Sakanaka M. Distribution of prosaposin-like immunoreactivity in rat brain. J Comp Neurol. 1993 Aug 22;334(4):590–602. doi: 10.1002/cne.903340407. [DOI] [PubMed] [Google Scholar]
  12. Lau K. H., Jennings J. C., Baylink D. J. Bovine skeletal growth factor stimulates protein phosphorylation of chicken bone cells in vitro. Int J Biochem. 1988;20(12):1443–1450. doi: 10.1016/s0020-711x(98)90014-3. [DOI] [PubMed] [Google Scholar]
  13. Morimoto S., Yamamoto Y., O'Brien J. S., Kishimoto Y. Determination of saposin proteins (sphingolipid activator proteins) in human tissues. Anal Biochem. 1990 Nov 1;190(2):154–157. doi: 10.1016/0003-2697(90)90173-7. [DOI] [PubMed] [Google Scholar]
  14. O'Brien J. S., Kishimoto Y. Saposin proteins: structure, function, and role in human lysosomal storage disorders. FASEB J. 1991 Mar 1;5(3):301–308. doi: 10.1096/fasebj.5.3.2001789. [DOI] [PubMed] [Google Scholar]
  15. O'Brien J. S., Kretz K. A., Dewji N., Wenger D. A., Esch F., Fluharty A. L. Coding of two sphingolipid activator proteins (SAP-1 and SAP-2) by same genetic locus. Science. 1988 Aug 26;241(4869):1098–1101. doi: 10.1126/science.2842863. [DOI] [PubMed] [Google Scholar]
  16. Rijnboutt S., Aerts H. M., Geuze H. J., Tager J. M., Strous G. J. Mannose 6-phosphate-independent membrane association of cathepsin D, glucocerebrosidase, and sphingolipid-activating protein in HepG2 cells. J Biol Chem. 1991 Mar 15;266(8):4862–4868. [PubMed] [Google Scholar]
  17. Sano A., Hineno T., Mizuno T., Kondoh K., Ueno S., Kakimoto Y., Inui K. Sphingolipid hydrolase activator proteins and their precursors. Biochem Biophys Res Commun. 1989 Dec 29;165(3):1191–1197. doi: 10.1016/0006-291x(89)92728-9. [DOI] [PubMed] [Google Scholar]
  18. Schengrund C. L. The role(s) of gangliosides in neural differentiation and repair: a perspective. Brain Res Bull. 1990 Jan;24(1):131–141. doi: 10.1016/0361-9230(90)90297-d. [DOI] [PubMed] [Google Scholar]
  19. Schnabel D., Schröder M., Fürst W., Klein A., Hurwitz R., Zenk T., Weber J., Harzer K., Paton B. C., Poulos A. Simultaneous deficiency of sphingolipid activator proteins 1 and 2 is caused by a mutation in the initiation codon of their common gene. J Biol Chem. 1992 Feb 15;267(5):3312–3315. [PubMed] [Google Scholar]
  20. Seeley P. J., Rukenstein A., Connolly J. L., Greene L. A. Differential inhibition of nerve growth factor and epidermal growth factor effects on the PC12 pheochromocytoma line. J Cell Biol. 1984 Feb;98(2):417–426. doi: 10.1083/jcb.98.2.417. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Sprecher-Levy H., Orr-Urtreger A., Lonai P., Horowitz M. Murine prosaposin: expression in the reproductive system of a gene implicated in human genetic diseases. Cell Mol Biol (Noisy-le-grand) 1993 May;39(3):287–299. [PubMed] [Google Scholar]
  22. Stahl N., Yancopoulos G. D. The alphas, betas, and kinases of cytokine receptor complexes. Cell. 1993 Aug 27;74(4):587–590. doi: 10.1016/0092-8674(93)90506-l. [DOI] [PubMed] [Google Scholar]
  23. Sylvester S. R., Skinner M. K., Griswold M. D. A sulfated glycoprotein synthesized by Sertoli cells and by epididymal cells is a component of the sperm membrane. Biol Reprod. 1984 Dec;31(5):1087–1101. doi: 10.1095/biolreprod31.5.1087. [DOI] [PubMed] [Google Scholar]
  24. Tsuji S., Arita M., Nagai Y. GQ1b, a bioactive ganglioside that exhibits novel nerve growth factor (NGF)-like activities in the two neuroblastoma cell lines. J Biochem. 1983 Jul;94(1):303–306. doi: 10.1093/oxfordjournals.jbchem.a134344. [DOI] [PubMed] [Google Scholar]
  25. Uemura K., Sugiyama E., Taketomi T. Effects of an inhibitor of glucosylceramide synthase on glycosphingolipid synthesis and neurite outgrowth in murine neuroblastoma cell lines. J Biochem. 1991 Jul;110(1):96–102. doi: 10.1093/oxfordjournals.jbchem.a123549. [DOI] [PubMed] [Google Scholar]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

RESOURCES