Abstract
A linear model of the liver cell adhesion molecule L-CAM from embryonic chickens is proposed in terms of its orientation on the cell surface, the number, type, and distribution of carbohydrate moieties, and sites of phosphorylation. L-CAM is isolated from cell membranes as a glycoprotein of Mr = 124,000. A soluble fragment (Ft1) of Mr = 81,000 can be released from cells by digestion with trypsin in the presence of calcium. Radiochemical amino acid sequence analyses indicated that both polypeptides have the same sequence for the first 10 amino acids, suggesting that fragment Ft1 contains the amino terminus of the L-CAM molecule and that the carboxyl-terminal portion of the peptide chain is associated with the cell. Digestions with endoglycosidase H and endoglycosidase F indicated that Ft1 has all of the N-linked carbohydrate groups associated with the larger species, including one high mannose oligosaccharide and three complex oligosaccharides. When hepatocytes were grown in the presence of 32PO4, 32P was detected in phosphoserine and phosphothreonine residues of intact L-CAM, but little or no 32P was detected in Ft1, suggesting that L-CAM is phosphorylated in the carboxyl-terminal region. On CNBr cleavage, the bulk of the 32P was detected in a single fragment of Mr = 20,000. The overall features of the L-CAM molecule incorporated in the model provide a basis for correlating its structure with its cell-cell binding activity and for detailed comparisons with similar molecules described in mammalian species.
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- Anderson D. J., Walter P., Blobel G. Signal recognition protein is required for the integration of acetylcholine receptor delta subunit, a transmembrane glycoprotein, into the endoplasmic reticulum membrane. J Cell Biol. 1982 May;93(2):501–506. doi: 10.1083/jcb.93.2.501. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brackenbury R., Thiery J. P., Rutishauser U., Edelman G. M. Adhesion among neural cells of the chick embryo. I. An immunological assay for molecules involved in cell-cell binding. J Biol Chem. 1977 Oct 10;252(19):6835–6840. [PubMed] [Google Scholar]
- Cunningham B. A., Hoffman S., Rutishauser U., Hemperly J. J., Edelman G. M. Molecular topography of the neural cell adhesion molecule N-CAM: surface orientation and location of sialic acid-rich and binding regions. Proc Natl Acad Sci U S A. 1983 May;80(10):3116–3120. doi: 10.1073/pnas.80.10.3116. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Damsky C. H., Richa J., Solter D., Knudsen K., Buck C. A. Identification and purification of a cell surface glycoprotein mediating intercellular adhesion in embryonic and adult tissue. Cell. 1983 Sep;34(2):455–466. doi: 10.1016/0092-8674(83)90379-3. [DOI] [PubMed] [Google Scholar]
- Edelman G. M. Cell adhesion molecules. Science. 1983 Feb 4;219(4584):450–457. doi: 10.1126/science.6823544. [DOI] [PubMed] [Google Scholar]
- Edelman G. M., Gallin W. J., Delouvée A., Cunningham B. A., Thiery J. P. Early epochal maps of two different cell adhesion molecules. Proc Natl Acad Sci U S A. 1983 Jul;80(14):4384–4388. doi: 10.1073/pnas.80.14.4384. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Elder J. H., Alexander S. endo-beta-N-acetylglucosaminidase F: endoglycosidase from Flavobacterium meningosepticum that cleaves both high-mannose and complex glycoproteins. Proc Natl Acad Sci U S A. 1982 Aug;79(15):4540–4544. doi: 10.1073/pnas.79.15.4540. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gallin W. J., Edelman G. M., Cunningham B. A. Characterization of L-CAM, a major cell adhesion molecule from embryonic liver cells. Proc Natl Acad Sci U S A. 1983 Feb;80(4):1038–1042. doi: 10.1073/pnas.80.4.1038. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hoffman S., Edelman G. M. Kinetics of homophilic binding by embryonic and adult forms of the neural cell adhesion molecule. Proc Natl Acad Sci U S A. 1983 Sep;80(18):5762–5766. doi: 10.1073/pnas.80.18.5762. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hunter T., Sefton B. M. Transforming gene product of Rous sarcoma virus phosphorylates tyrosine. Proc Natl Acad Sci U S A. 1980 Mar;77(3):1311–1315. doi: 10.1073/pnas.77.3.1311. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hyafil F., Morello D., Babinet C., Jacob F. A cell surface glycoprotein involved in the compaction of embryonal carcinoma cells and cleavage stage embryos. Cell. 1980 Oct;21(3):927–934. doi: 10.1016/0092-8674(80)90456-0. [DOI] [PubMed] [Google Scholar]
- Kübler D., Pyerin W., Kinzel V. Protein kinase activity and substrates at the surface of intact HeLa cells. J Biol Chem. 1982 Jan 10;257(1):322–329. [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
- Ogou S. I., Yoshida-Noro C., Takeichi M. Calcium-dependent cell-cell adhesion molecules common to hepatocytes and teratocarcinoma stem cells. J Cell Biol. 1983 Sep;97(3):944–948. doi: 10.1083/jcb.97.3.944. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Peyriéras N., Hyafil F., Louvard D., Ploegh H. L., Jacob F. Uvomorulin: a nonintegral membrane protein of early mouse embryo. Proc Natl Acad Sci U S A. 1983 Oct;80(20):6274–6277. doi: 10.1073/pnas.80.20.6274. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rothbard J. B., Hopp T. P., Edelman G. M., Cunningham B. A. Structure of the heavy chain of the H-2Kk histocompatibility antigen. Proc Natl Acad Sci U S A. 1980 Jul;77(7):4239–4243. doi: 10.1073/pnas.77.7.4239. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rutishauser U., Thiery J. P., Brackenbury R., Edelman G. M. Adhesion among neural cells of the chick embryo. III. Relationship of the surface molecule CAM to cell adhesion and the development of histotypic patterns. J Cell Biol. 1978 Nov;79(2 Pt 1):371–381. doi: 10.1083/jcb.79.2.371. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tarentino A. L., Maley F. Purification and properties of an endo-beta-N-acetylglucosaminidase from Streptomyces griseus. J Biol Chem. 1974 Feb 10;249(3):811–817. [PubMed] [Google Scholar]
- Thiery J. P., Delouvée A., Gallin W. J., Cunningham B. A., Edelman G. M. Ontogenetic expression of cell adhesion molecules: L-CAM is found in epithelia derived from the three primary germ layers. Dev Biol. 1984 Mar;102(1):61–78. doi: 10.1016/0012-1606(84)90175-1. [DOI] [PubMed] [Google Scholar]
- Thiery J. P., Duband J. L., Rutishauser U., Edelman G. M. Cell adhesion molecules in early chicken embryogenesis. Proc Natl Acad Sci U S A. 1982 Nov;79(21):6737–6741. doi: 10.1073/pnas.79.21.6737. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yoshida-Noro C., Suzuki N., Takeichi M. Molecular nature of the calcium-dependent cell-cell adhesion system in mouse teratocarcinoma and embryonic cells studied with a monoclonal antibody. Dev Biol. 1984 Jan;101(1):19–27. doi: 10.1016/0012-1606(84)90112-x. [DOI] [PubMed] [Google Scholar]