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. 2001 Sep;159(1):219–228. doi: 10.1093/genetics/159.1.219

The protein 4.1, ezrin, radixin, moesin (FERM) domain of Drosophila Coracle, a cytoplasmic component of the septate junction, provides functions essential for embryonic development and imaginal cell proliferation.

R E Ward 4th 1, L Schweizer 1, R S Lamb 1, R G Fehon 1
PMCID: PMC1461787  PMID: 11560899

Abstract

Coracle is a member of the Protein 4.1 superfamily of proteins, whose members include Protein 4.1, the Neurofibromatosis 2 tumor suppressor Merlin, Expanded, the ERM proteins, protein tyrosine phosphatases, and unconventional myosins. Recent evidence suggests that members of this family participate in cell signaling events, including those that regulate cell proliferation and the cytoskeleton. Previously, we demonstrated that Coracle protein is localized to the septate junction in epithelial cells and is required for septate junction integrity. Loss of coracle function leads to defects in embryonic development, including failure in dorsal closure, and to proliferation defects. In addition, we determined that the N-terminal 383 amino acids define an essential functional domain possessing membrane-organizing properties. Here we investigate the full range of functions provided by this highly conserved domain and find that it is sufficient to rescue all embryonic defects associated with loss of coracle function. In addition, this domain is sufficient to rescue the reduced cell proliferation defect in imaginal discs, although it is incapable of rescuing null mutants to the adult stage. This result suggests the presence of a second functional domain within Coracle, a notion supported by molecular characterization of a series of coracle alleles.

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Selected References

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  1. Adams M. D., Celniker S. E., Holt R. A., Evans C. A., Gocayne J. D., Amanatides P. G., Scherer S. E., Li P. W., Hoskins R. A., Galle R. F. The genome sequence of Drosophila melanogaster. Science. 2000 Mar 24;287(5461):2185–2195. doi: 10.1126/science.287.5461.2185. [DOI] [PubMed] [Google Scholar]
  2. Algrain M., Turunen O., Vaheri A., Louvard D., Arpin M. Ezrin contains cytoskeleton and membrane binding domains accounting for its proposed role as a membrane-cytoskeletal linker. J Cell Biol. 1993 Jan;120(1):129–139. doi: 10.1083/jcb.120.1.129. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Anderson R. A., Lovrien R. E. Glycophorin is linked by band 4.1 protein to the human erythrocyte membrane skeleton. Nature. 1984 Feb 16;307(5952):655–658. doi: 10.1038/307655a0. [DOI] [PubMed] [Google Scholar]
  4. Bellen H. J., Lu Y., Beckstead R., Bhat M. A. Neurexin IV, caspr and paranodin--novel members of the neurexin family: encounters of axons and glia. Trends Neurosci. 1998 Oct;21(10):444–449. doi: 10.1016/s0166-2236(98)01267-3. [DOI] [PubMed] [Google Scholar]
  5. Boedigheimer M., Laughon A. Expanded: a gene involved in the control of cell proliferation in imaginal discs. Development. 1993 Aug;118(4):1291–1301. doi: 10.1242/dev.118.4.1291. [DOI] [PubMed] [Google Scholar]
  6. Brand A. H., Perrimon N. Targeted gene expression as a means of altering cell fates and generating dominant phenotypes. Development. 1993 Jun;118(2):401–415. doi: 10.1242/dev.118.2.401. [DOI] [PubMed] [Google Scholar]
  7. Bretscher A. Regulation of cortical structure by the ezrin-radixin-moesin protein family. Curr Opin Cell Biol. 1999 Feb;11(1):109–116. doi: 10.1016/s0955-0674(99)80013-1. [DOI] [PubMed] [Google Scholar]
  8. Burke R., Basler K. Dpp receptors are autonomously required for cell proliferation in the entire developing Drosophila wing. Development. 1996 Jul;122(7):2261–2269. doi: 10.1242/dev.122.7.2261. [DOI] [PubMed] [Google Scholar]
  9. Chishti A. H., Kim A. C., Marfatia S. M., Lutchman M., Hanspal M., Jindal H., Liu S. C., Low P. S., Rouleau G. A., Mohandas N. The FERM domain: a unique module involved in the linkage of cytoplasmic proteins to the membrane. Trends Biochem Sci. 1998 Aug;23(8):281–282. doi: 10.1016/s0968-0004(98)01237-7. [DOI] [PubMed] [Google Scholar]
  10. Correas I., Leto T. L., Speicher D. W., Marchesi V. T. Identification of the functional site of erythrocyte protein 4.1 involved in spectrin-actin associations. J Biol Chem. 1986 Mar 5;261(7):3310–3315. [PubMed] [Google Scholar]
  11. Fehon R. G., Dawson I. A., Artavanis-Tsakonas S. A Drosophila homologue of membrane-skeleton protein 4.1 is associated with septate junctions and is encoded by the coracle gene. Development. 1994 Mar;120(3):545–557. doi: 10.1242/dev.120.3.545. [DOI] [PubMed] [Google Scholar]
  12. Gary R., Bretscher A. Ezrin self-association involves binding of an N-terminal domain to a normally masked C-terminal domain that includes the F-actin binding site. Mol Biol Cell. 1995 Aug;6(8):1061–1075. doi: 10.1091/mbc.6.8.1061. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Hoover K. B., Bryant P. J. The genetics of the protein 4.1 family: organizers of the membrane and cytoskeleton. Curr Opin Cell Biol. 2000 Apr;12(2):229–234. doi: 10.1016/s0955-0674(99)00080-0. [DOI] [PubMed] [Google Scholar]
  14. Johnston L. A., Edgar B. A. Wingless and Notch regulate cell-cycle arrest in the developing Drosophila wing. Nature. 1998 Jul 2;394(6688):82–84. doi: 10.1038/27925. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. LaJeunesse D. R., McCartney B. M., Fehon R. G. Structural analysis of Drosophila merlin reveals functional domains important for growth control and subcellular localization. J Cell Biol. 1998 Jun 29;141(7):1589–1599. doi: 10.1083/jcb.141.7.1589. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Lamb R. S., Ward R. E., Schweizer L., Fehon R. G. Drosophila coracle, a member of the protein 4.1 superfamily, has essential structural functions in the septate junctions and developmental functions in embryonic and adult epithelial cells. Mol Biol Cell. 1998 Dec;9(12):3505–3519. doi: 10.1091/mbc.9.12.3505. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Marchesi V. T. Stabilizing infrastructure of cell membranes. Annu Rev Cell Biol. 1985;1:531–561. doi: 10.1146/annurev.cb.01.110185.002531. [DOI] [PubMed] [Google Scholar]
  18. Mattagajasingh S. N., Huang S. C., Hartenstein J. S., Snyder M., Marchesi V. T., Benz E. J. A nonerythroid isoform of protein 4.1R interacts with the nuclear mitotic apparatus (NuMA) protein. J Cell Biol. 1999 Apr 5;145(1):29–43. doi: 10.1083/jcb.145.1.29. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. McCartney B. M., Kulikauskas R. M., LaJeunesse D. R., Fehon R. G. The neurofibromatosis-2 homologue, Merlin, and the tumor suppressor expanded function together in Drosophila to regulate cell proliferation and differentiation. Development. 2000 Mar;127(6):1315–1324. doi: 10.1242/dev.127.6.1315. [DOI] [PubMed] [Google Scholar]
  20. Morrison H., Sherman L. S., Legg J., Banine F., Isacke C., Haipek C. A., Gutmann D. H., Ponta H., Herrlich P. The NF2 tumor suppressor gene product, merlin, mediates contact inhibition of growth through interactions with CD44. Genes Dev. 2001 Apr 15;15(8):968–980. doi: 10.1101/gad.189601. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Pasternack G. R., Anderson R. A., Leto T. L., Marchesi V. T. Interactions between protein 4.1 and band 3. An alternative binding site for an element of the membrane skeleton. J Biol Chem. 1985 Mar 25;260(6):3676–3683. [PubMed] [Google Scholar]
  22. Rebay I., Fehon R. G., Artavanis-Tsakonas S. Specific truncations of Drosophila Notch define dominant activated and dominant negative forms of the receptor. Cell. 1993 Jul 30;74(2):319–329. doi: 10.1016/0092-8674(93)90423-n. [DOI] [PubMed] [Google Scholar]
  23. Reczek D., Bretscher A. The carboxyl-terminal region of EBP50 binds to a site in the amino-terminal domain of ezrin that is masked in the dormant molecule. J Biol Chem. 1998 Jul 17;273(29):18452–18458. doi: 10.1074/jbc.273.29.18452. [DOI] [PubMed] [Google Scholar]
  24. Rouleau G. A., Merel P., Lutchman M., Sanson M., Zucman J., Marineau C., Hoang-Xuan K., Demczuk S., Desmaze C., Plougastel B. Alteration in a new gene encoding a putative membrane-organizing protein causes neuro-fibromatosis type 2. Nature. 1993 Jun 10;363(6429):515–521. doi: 10.1038/363515a0. [DOI] [PubMed] [Google Scholar]
  25. Trofatter J. A., MacCollin M. M., Rutter J. L., Murrell J. R., Duyao M. P., Parry D. M., Eldridge R., Kley N., Menon A. G., Pulaski K. A novel moesin-, ezrin-, radixin-like gene is a candidate for the neurofibromatosis 2 tumor suppressor. Cell. 1993 Mar 12;72(5):791–800. doi: 10.1016/0092-8674(93)90406-g. [DOI] [PubMed] [Google Scholar]
  26. Tsukita S., Oishi K., Sato N., Sagara J., Kawai A., Tsukita S. ERM family members as molecular linkers between the cell surface glycoprotein CD44 and actin-based cytoskeletons. J Cell Biol. 1994 Jul;126(2):391–401. doi: 10.1083/jcb.126.2.391. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Tsukita S., Yonemura S. Cortical actin organization: lessons from ERM (ezrin/radixin/moesin) proteins. J Biol Chem. 1999 Dec 3;274(49):34507–34510. doi: 10.1074/jbc.274.49.34507. [DOI] [PubMed] [Google Scholar]
  28. Turunen O., Wahlström T., Vaheri A. Ezrin has a COOH-terminal actin-binding site that is conserved in the ezrin protein family. J Cell Biol. 1994 Sep;126(6):1445–1453. doi: 10.1083/jcb.126.6.1445. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Walensky L. D., Gascard P., Fields M. E., Blackshaw S., Conboy J. G., Mohandas N., Snyder S. H. The 13-kD FK506 binding protein, FKBP13, interacts with a novel homologue of the erythrocyte membrane cytoskeletal protein 4.1. J Cell Biol. 1998 Apr 6;141(1):143–153. doi: 10.1083/jcb.141.1.143. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Ward R. E., 4th, Lamb R. S., Fehon R. G. A conserved functional domain of Drosophila coracle is required for localization at the septate junction and has membrane-organizing activity. J Cell Biol. 1998 Mar 23;140(6):1463–1473. doi: 10.1083/jcb.140.6.1463. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Ye K., Compton D. A., Lai M. M., Walensky L. D., Snyder S. H. Protein 4.1N binding to nuclear mitotic apparatus protein in PC12 cells mediates the antiproliferative actions of nerve growth factor. J Neurosci. 1999 Dec 15;19(24):10747–10756. doi: 10.1523/JNEUROSCI.19-24-10747.1999. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Ye K., Hurt K. J., Wu F. Y., Fang M., Luo H. R., Hong J. J., Blackshaw S., Ferris C. D., Snyder S. H. Pike. A nuclear gtpase that enhances PI3kinase activity and is regulated by protein 4.1N. Cell. 2000 Dec 8;103(6):919–930. doi: 10.1016/s0092-8674(00)00195-1. [DOI] [PubMed] [Google Scholar]
  33. Yonemura S., Hirao M., Doi Y., Takahashi N., Kondo T., Tsukita S., Tsukita S. Ezrin/radixin/moesin (ERM) proteins bind to a positively charged amino acid cluster in the juxta-membrane cytoplasmic domain of CD44, CD43, and ICAM-2. J Cell Biol. 1998 Feb 23;140(4):885–895. doi: 10.1083/jcb.140.4.885. [DOI] [PMC free article] [PubMed] [Google Scholar]

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