Abstract
In a previous study we showed, by transient expression studies in COS-1 cells, that the C-terminal domain of rat intestinal membrane mucin Muc3 was cleaved between glycine and serine within a GSIVV (one-letter) amino acid sequence during its residence in the endoplasmic reticulum. The extracellular domain fragment remained linked to the membrane-associated fragment by non-covalent interactions. The present study demonstrates that cleavage depends not only on the presence of the G/SIVV site (where G/S is the glycine downward arrow serine cleavage site), but also on more distant C-terminal sequences in the SEA (sea-urchin sperm protein, enterokinase and agrin) module. Inhibition of N-glycosylation by tunicamycin treatment of transfected cells did not prevent re-association of fragments, although cleavage was partially impaired, as some of the non-glycosylated, non-cleaved products were seen to accumulate in cells. Membrane targeting of the Muc3 domain and its cleavage products occurred in transfected cells and was not impaired in mutants in which the cleavage site was mutated. Targeting was also not impaired for products devoid of N-linked oligosaccharides. Our studies thus indicate that (a) cleavage within the SEA module of rat Muc3 requires participation of peptide sequences located C-terminal of and distant from the cleavage site, (b) re-association of the fragments requires the SEA module, but is independent of N-linked oligosaccharides, and (c) membrane targeting of the mucin is independent of the SEA-module-cleavage reaction.
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- Abe Jumpei, Fukuzawa Taku, Hirose Shigehisa. Cleavage of Ig-Hepta at a "SEA" module and at a conserved G protein-coupled receptor proteolytic site. J Biol Chem. 2002 Apr 24;277(26):23391–23398. doi: 10.1074/jbc.M110877200. [DOI] [PubMed] [Google Scholar]
- Baruch A., Hartmann M., Yoeli M., Adereth Y., Greenstein S., Stadler Y., Skornik Y., Zaretsky J., Smorodinsky N. I., Keydar I. The breast cancer-associated MUC1 gene generates both a receptor and its cognate binding protein. Cancer Res. 1999 Apr 1;59(7):1552–1561. [PubMed] [Google Scholar]
- Bork P., Patthy L. The SEA module: a new extracellular domain associated with O-glycosylation. Protein Sci. 1995 Jul;4(7):1421–1425. doi: 10.1002/pro.5560040716. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Buisine M. P., Desreumaux P., Leteurtre E., Copin M. C., Colombel J. F., Porchet N., Aubert J. P. Mucin gene expression in intestinal epithelial cells in Crohn's disease. Gut. 2001 Oct;49(4):544–551. doi: 10.1136/gut.49.4.544. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Carraway K. L., 3rd, Rossi E. A., Komatsu M., Price-Schiavi S. A., Huang D., Guy P. M., Carvajal M. E., Fregien N., Carraway C. A., Carraway K. L. An intramembrane modulator of the ErbB2 receptor tyrosine kinase that potentiates neuregulin signaling. J Biol Chem. 1999 Feb 26;274(9):5263–5266. doi: 10.1074/jbc.274.9.5263. [DOI] [PubMed] [Google Scholar]
- Carraway K. L., Price-Schiavi S. A., Komatsu M., Idris N., Perez A., Li P., Jepson S., Zhu X., Carvajal M. E., Carraway C. A. Multiple facets of sialomucin complex/MUC4, a membrane mucin and erbb2 ligand, in tumors and tissues (Y2K update). Front Biosci. 2000 Jan 1;5:D95–D107. doi: 10.2741/carraway. [DOI] [PubMed] [Google Scholar]
- Carraway Kermit L., Ramsauer Victoria P., Haq Bushra, Carothers Carraway Coralie A. Cell signaling through membrane mucins. Bioessays. 2003 Jan;25(1):66–71. doi: 10.1002/bies.10201. [DOI] [PubMed] [Google Scholar]
- Gum James R., Jr, Crawley Suzanne C., Hicks James W., Szymkowski David E., Kim Young S. MUC17, a novel membrane-tethered mucin. Biochem Biophys Res Commun. 2002 Mar 1;291(3):466–475. doi: 10.1006/bbrc.2002.6475. [DOI] [PubMed] [Google Scholar]
- Hanisch F. G., Müller S. MUC1: the polymorphic appearance of a human mucin. Glycobiology. 2000 May;10(5):439–449. doi: 10.1093/glycob/10.5.439. [DOI] [PubMed] [Google Scholar]
- Julian JoAnne, Carson Daniel D. Formation of MUC1 metabolic complex is conserved in tumor-derived and normal epithelial cells. Biochem Biophys Res Commun. 2002 May 17;293(4):1183–1190. doi: 10.1016/S0006-291X(02)00352-2. [DOI] [PubMed] [Google Scholar]
- Khatri I. A., Forstner G. G., Forstner J. F. The carboxyl-terminal sequence of rat intestinal mucin RMuc3 contains a putative transmembrane region and two EGF-like motifs. Biochim Biophys Acta. 1997 May 22;1326(1):7–11. doi: 10.1016/s0005-2736(97)00063-1. [DOI] [PubMed] [Google Scholar]
- Khatri I. A., Ho C., Specian R. D., Forstner J. F. Characteristics of rodent intestinal mucin Muc3 and alterations in a mouse model of human cystic fibrosis. Am J Physiol Gastrointest Liver Physiol. 2001 Jun;280(6):G1321–G1330. doi: 10.1152/ajpgi.2001.280.6.G1321. [DOI] [PubMed] [Google Scholar]
- Ligtenberg M. J., Kruijshaar L., Buijs F., van Meijer M., Litvinov S. V., Hilkens J. Cell-associated episialin is a complex containing two proteins derived from a common precursor. J Biol Chem. 1992 Mar 25;267(9):6171–6177. [PubMed] [Google Scholar]
- McNeer R. R., Huang D., Fregien N. L., Carraway K. L. Sialomucin complex in the rat respiratory tract: a model for its role in epithelial protection. Biochem J. 1998 Mar 1;330(Pt 2):737–744. doi: 10.1042/bj3300737. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Parmley R. R., Gendler S. J. Cystic fibrosis mice lacking Muc1 have reduced amounts of intestinal mucus. J Clin Invest. 1998 Nov 15;102(10):1798–1806. doi: 10.1172/JCI3820. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Parry S., Silverman H. S., McDermott K., Willis A., Hollingsworth M. A., Harris A. Identification of MUC1 proteolytic cleavage sites in vivo. Biochem Biophys Res Commun. 2001 May 11;283(3):715–720. doi: 10.1006/bbrc.2001.4775. [DOI] [PubMed] [Google Scholar]
- Satyanarayana J., Gururaja T. L., Narasimhamurthy S., Naganagowda G. A., Levine M. J. Synthesis and conformational features of human salivary mucin C-terminal derived peptide epitope carrying Thomsen-Friedenreich antigen: implications for its role in self-association. Biopolymers. 2001 Apr 15;58(5):500–510. doi: 10.1002/1097-0282(20010415)58:5<500::AID-BIP1025>3.0.CO;2-5. [DOI] [PubMed] [Google Scholar]
- Schroeder J. A., Thompson M. C., Gardner M. M., Gendler S. J. Transgenic MUC1 interacts with epidermal growth factor receptor and correlates with mitogen-activated protein kinase activation in the mouse mammary gland. J Biol Chem. 2001 Jan 22;276(16):13057–13064. doi: 10.1074/jbc.M011248200. [DOI] [PubMed] [Google Scholar]
- Sheng Z., Wu K., Carraway K. L., Fregien N. Molecular cloning of the transmembrane component of the 13762 mammary adenocarcinoma sialomucin complex. A new member of the epidermal growth factor superfamily. J Biol Chem. 1992 Aug 15;267(23):16341–16346. [PubMed] [Google Scholar]
- Shirazi T., Longman R. J., Corfield A. P., Probert C. S. Mucins and inflammatory bowel disease. Postgrad Med J. 2000 Aug;76(898):473–478. doi: 10.1136/pmj.76.898.473. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Smorodinsky N., Weiss M., Hartmann M. L., Baruch A., Harness E., Yaakobovitz M., Keydar I., Wreschner D. H. Detection of a secreted MUC1/SEC protein by MUC1 isoform specific monoclonal antibodies. Biochem Biophys Res Commun. 1996 Nov 1;228(1):115–121. doi: 10.1006/bbrc.1996.1625. [DOI] [PubMed] [Google Scholar]
- Stacey M., Lin H. H., Gordon S., McKnight A. J. LNB-TM7, a group of seven-transmembrane proteins related to family-B G-protein-coupled receptors. Trends Biochem Sci. 2000 Jun;25(6):284–289. doi: 10.1016/s0968-0004(00)01583-8. [DOI] [PubMed] [Google Scholar]
- Wang Rongquan, Khatri Ismat A., Forstner Janet F. C-terminal domain of rodent intestinal mucin Muc3 is proteolytically cleaved in the endoplasmic reticulum to generate extracellular and membrane components. Biochem J. 2002 Sep 1;366(Pt 2):623–631. doi: 10.1042/BJ20020289. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wreschner Daniel H., McGuckin Michael A., Williams Stefanie J., Baruch Amos, Yoeli Merav, Ziv Ravit, Okun Liron, Zaretsky Joseph, Smorodinsky Nechama, Keydar Iafa. Generation of ligand-receptor alliances by "SEA" module-mediated cleavage of membrane-associated mucin proteins. Protein Sci. 2002 Mar;11(3):698–706. doi: 10.1110/ps.16502. [DOI] [PMC free article] [PubMed] [Google Scholar]