Amino-terminal basic residues of Src mediate membrane binding through electrostatic interaction with acidic phospholipids Journal Article
| Authors: | Sigal, C. T.; Zhou, W.; Buser, C. A.; McLaughlin, S.; Resh, M. D. |
| Article Title: | Amino-terminal basic residues of Src mediate membrane binding through electrostatic interaction with acidic phospholipids |
| Abstract: | Membrane targeting of pp60(src) (Src) is mediated by its myristoylated amino terminus. We demonstrate that, in addition to myristate, six basic residues in the amino terminus are essential for high-affinity binding to the lipid bilayer via electrostatic interaction with acidic phospholipids. Specifically, c-Src was shown to bind 2500-fold more strongly to vesicles composed of the physiological ratio of 2:1 phosphatidylcholine (PC)/phosphatidylserine (PS) than to neutral PC bilayer vesicles. The apparent K(d) for binding of c-Src to the PC/PS bilayer was 6 x 10-7 M. This interaction is sufficiently strong to account for c-Src membrane targeting. Mutants of c-Src in which the amino-terminal basic residues were replaced by neutral asparagine residues exhibited binding isotherms approaching that of wild-type binding to neutral bilayers (apparent K(d) of 2 x 10-3 M). The transforming v-Src and activated c-Src (Y527F) proteins also bound more strongly to PC/PS bilayers (apparent K(d) of ≃1 x 10-5 M) than to neutral PC bilayers. In vivo experiments with Src mutants confirmed the role of positive charge in mediating membrane binding and cellular transformation. |
| Keywords: | gene mutation; nonhuman; comparative study; binding affinity; animal cell; mouse; animal; mice; amino acid substitution; protein binding; transfection; structure-activity relationship; animalia; amino acid sequence; molecular sequence data; amino terminal sequence; kinetics; cell transformation; recombinant proteins; mutagenesis, site-directed; binding sites; conformational transition; point mutation; oligopeptides; cell strain 3t3; lipid bilayers; phosphatidylcholine; lipid bilayer; membrane binding; 3t3 cells; transformation; phospholipids; binding, competitive; protein kinase p60; phospholipid membrane; phosphatidylserine; electrostatics; electrochemistry; oncogene protein pp60(v-src); membrane potential; priority journal; article; support, non-u.s. gov't; support, u.s. gov't, p.h.s.; support, u.s. gov't, non-p.h.s.; myristate; proto-oncogene protein pp60(c-src); protein-membrane interactions |
| Journal Title: | Proceedings of the National Academy of Sciences of the United States of America |
| Volume: | 91 |
| Issue: | 25 |
| ISSN: | 0027-8424 |
| Publisher: | National Academy of Sciences |
| Date Published: | 1994-12-06 |
| Start Page: | 12253 |
| End Page: | 12257 |
| Language: | English |
| DOI: | 10.1073/pnas.91.25.12253 |
| PROVIDER: | scopus |
| PMCID: | PMC45415 |
| PUBMED: | 7527558 |
| DOI/URL: | |
| Notes: | Export Date: 14 January 2019 -- Article -- CODEN: PNASA C2 -- Source: Scopus |
