Transthyretin interacts with the lysosome-associated membrane protein (LAMP-1) in circulation
| Autor: | Greg Hodge, Litsa Karageorgos, Tom Litjens, Chi T. Hua, Melissa Chang, Elizabeth L. Isaac, Peter J. Meikle |
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| Rok vydání: | 2004 |
| Předmět: |
genetic structures
Fibrosarcoma Biology Biochemistry Affinity chromatography Antigens CD Cell Line Tumor Lysosome medicine Humans Prealbumin Protein Isoforms Lysosome-associated membrane glycoprotein Molecular Biology Galectin chemistry.chemical_classification Lysosome-Associated Membrane Glycoproteins Cholic Acids Blood Proteins Cell Biology Recombinant Proteins eye diseases Amino acid Gene Expression Regulation Neoplastic Alternative Splicing medicine.anatomical_structure chemistry Membrane protein Biophysics sense organs Glycoprotein Research Article Homotetramer |
| Zdroj: | Biochemical Journal. 382:481-489 |
| ISSN: | 1470-8728 0264-6021 |
| DOI: | 10.1042/bj20031752 |
| Popis: | LAMP-1 (lysosome-associated membrane protein), a major glycoprotein present in the lysosomal membrane, constitutes up to 50% of total membrane proteins. LAMP-1, expressed at the plasma membrane, is reported to be the major molecule expressing the sialyl-Lewis X antigen. Two forms of LAMP-1 exist; the full-length LAMP-1 [LAMP-1 (+Tail)] has a highly glycosylated lumenal domain, a membrane-spanning domain and a short cytoplasmic tail, and the truncated LAMP-1 [LAMP-1 (−Tail)] contains only the lumenal domain. Soluble LAMP-1 (±Tail) has been reported in circulation. LAMP-1 at the cell surface has been shown to interact with E-selectin and galectin and is proposed to function in cell–cell interactions. However, the functional role(s) of soluble LAMP-1 in circulation is unclear. To investigate the functional role of soluble LAMP-1 in circulation, recombinant LAMP-1 (−Tail) and LAMP-1 (+Tail) were produced in HT1080 cells. Two immune-quantification assays were developed to distinguish between the LAMP-1 forms. The interaction and aggregation properties of the different LAMP-1 forms were investigated using the immune-quantification assays. Only LAMP-1 (+Tail) was found to aggregate and interact with plasma proteins. Plasma proteins that interact with LAMP-1 were isolated by affinity chromatography with either the recombinant LAMP-1 (−Tail) or a synthesized peptide consisting of the 14 amino acids of the LAMP-1 cytoplasmic tail. Transthyretin was found to interact with the cytoplasmic tail of LAMP-1. Transthyretin exists as a homotetramer in plasma, as such may play a role in the aggregation of LAMP-1 in circulation. |
| Databáze: | OpenAIRE |
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