A1 Refereed original research article in a scientific journal
Mechanism and biological role of profilin-Srv2/CAP interaction
Authors: Bertling E, Quintero-Monzon O, Mattila PK, Goode BL, Lappalainen P
Publisher: COMPANY OF BIOLOGISTS LTD
Publication year: 2007
Journal: Journal of Cell Science
Journal name in source: JOURNAL OF CELL SCIENCE
Journal acronym: J CELL SCI
Volume: 120
Issue: 7
First page : 1225
Last page: 1234
Number of pages: 10
ISSN: 0021-9533
DOI: https://doi.org/10.1242/jcs.000158
Abstract
Profilin and cyclase-associated protein (CAP, known in yeast as Srv2) are ubiquitous and abundant actin monomer- binding proteins. Profilin catalyses the nucleotide exchange on actin monomers and promotes their addition to filament barbed ends. Srv2/CAP recycles newly depolymerized actin monomers from ADF/cofilin for subsequent rounds of polymerization. Srv2/CAP also harbors two proline- rich motifs and has been suggested to interact with profilin. However, the mechanism and biological role of the possible profilin-Srv2/CAP interaction has not been investigated. Here, we show that Saccharomyces cerevisiae Srv2 and profilin interact directly (K-D similar to 1.3 mu M) and demonstrate that a specific proline-rich motif in Srv2 mediates this interaction in vitro and in vivo. ADP- actin monomers and profilin do not interfere with each other's binding to Srv2, suggesting that these three proteins can form a ternary complex. Genetic and cell biological analyses on an Srv2 allele (srv2-201) defective in binding profilin reveals that a direct interaction with profilin is not essential for Srv2 cellular function. However, srv2-201 causes a moderate increase in cell size and partially suppresses the cell growth and actin organization defects of an actin binding mutant profilin (pfy1-4). Together these data suggest that Srv2 is an important physiological interaction partner of profilin.
Profilin and cyclase-associated protein (CAP, known in yeast as Srv2) are ubiquitous and abundant actin monomer- binding proteins. Profilin catalyses the nucleotide exchange on actin monomers and promotes their addition to filament barbed ends. Srv2/CAP recycles newly depolymerized actin monomers from ADF/cofilin for subsequent rounds of polymerization. Srv2/CAP also harbors two proline- rich motifs and has been suggested to interact with profilin. However, the mechanism and biological role of the possible profilin-Srv2/CAP interaction has not been investigated. Here, we show that Saccharomyces cerevisiae Srv2 and profilin interact directly (K-D similar to 1.3 mu M) and demonstrate that a specific proline-rich motif in Srv2 mediates this interaction in vitro and in vivo. ADP- actin monomers and profilin do not interfere with each other's binding to Srv2, suggesting that these three proteins can form a ternary complex. Genetic and cell biological analyses on an Srv2 allele (srv2-201) defective in binding profilin reveals that a direct interaction with profilin is not essential for Srv2 cellular function. However, srv2-201 causes a moderate increase in cell size and partially suppresses the cell growth and actin organization defects of an actin binding mutant profilin (pfy1-4). Together these data suggest that Srv2 is an important physiological interaction partner of profilin.
Downloadable publication This is an electronic reprint of the original article. |  |
UTU Research Portal