Biosynthesis of glycosylphosphatidylinositol (GPI)-anchored membrane proteins in intact cells: specific amino acid requirements adjacent to the site of cleavage and GPI attachment
| Autor: | Sidney Udenfriend, Louise Gerber, Rodolfo Amthauer, Larry Brink, Krishna Kodukula |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1993 |
| Předmět: |
Signal peptide
Glycosylphosphatidylinositols Placenta Molecular Sequence Data Fluorescent Antibody Technique Biology Protein Sorting Signals Transfection Protein Structure Secondary Cell Line Serine Pregnancy Animals Humans Amino Acid Sequence Threonine Amino Acids Peptide sequence chemistry.chemical_classification Alanine Signal peptidase Cell-Free System Membrane Proteins Cell Biology Articles Alkaline Phosphatase Molecular biology Immunohistochemistry Recombinant Proteins Amino acid Membrane protein Biochemistry chemistry Mutagenesis Site-Directed Female Plasmids |
| Zdroj: | The Journal of Cell Biology |
| ISSN: | 1540-8140 0021-9525 |
| Popis: | Mutational studies were previously carried out at the omega site intact cells (Micanovic, R., L. Gerber, J. Berger, K. Kodukula, and S. Udenfriend. 1990. Proc. Natl. Acad. Sci. USA. 87:157-161; Micanovic R., K. Kodukula, L. Gerber, and S. Udenfriend. 1990. Proc. Natl. Acad. Sci. USA: 87:7939-7943) and at the omega + 1 and omega + 2 sites in a cell-free system (Gerber, L., K. Kodukula, and S. Udenfriend. 1992. J. Biol. Chem. 267:12168-12173) of nascent proteins destined to be processed to a glycosylphosphatidyl-inositol (GPI)-anchored form. We have now mutated the omega + 1 and omega + 2 sites in placental alkaline phosphatase (PLAP) cDNA and transfected the wild-type and mutant cDNAs into COS 7 cells. Only glycine at the omega + 2 site yielded enzymatically active GPI membrane-anchored PLAP in amounts comparable to the wild type (alanine). Serine was less active and threonine and valine yielded very low but significant activity. By contrast the omega + 1 site was promiscuous, with only proline being inactive. These and the previous studies indicate that the omega and omega + 2 sites of a nascent protein are key determinants for recognition by COOH-terminal signal transamidase. Comparisons have been made to specific requirements for substitution at the -1, -3 sites of amino terminal signal peptides for recognition by NH2-terminal signal peptidase and the mechanisms of NH2 and COOH-terminal signaling are compared. |
| Databáze: | OpenAIRE |
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