title: eEF1A is an S-RNase binding factor in self-incompatible Solanum chacoense.
abstract: Self-incompatibility (SI) is a genetic mechanism that allows flowering plants to identify and block fertilization by self-pollen. In the Solanaceae, SI is controlled by a multiallelic S-locus encoding both S-RNases and F-box proteins as female and male determinants, respectively. S-RNase activity is essential for pollen rejection, and a minimum threshold value of S-RNases in the style is also required. Here we present biochemical evidence that eEF1A is a novel S-RNase-binding partner in vitro. We further show that the normal actin binding activity of eEF1A is enhanced by the presence of S-RNase. Lastly, we find that there is a co-localization of S-RNase and actin in the incompatible pollen tubes in structures reminiscent of the actin bundles formed by eEF1A. We propose that increased binding of eEF1A to actin in the presence of S-RNase could help explain the disruption of the actin cytoskeleton observed during SI reactions.
authors.affiliation: Institut de Recherche en Biologie Végétale (IRBV), Département de Sciences Biologiques, Université de Montréal, Montréal, Québec, Canada.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Soulard
authors.affiliation: Institut de Recherche en Biologie Végétale (IRBV), Département de Sciences Biologiques, Université de Montréal, Montréal, Québec, Canada.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Boivin
authors.affiliation: Institut de Recherche en Biologie Végétale (IRBV), Département de Sciences Biologiques, Université de Montréal, Montréal, Québec, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Morse
authors.affiliation: Institut de Recherche en Biologie Végétale (IRBV), Département de Sciences Biologiques, Université de Montréal, Montréal, Québec, Canada.
authors.forename: Mario
authors.initials: M
authors.lastname: Cappadocia
mesh_terms: D000199:Actins / Q000378:metabolism; D020648:Peptide Elongation Factor 1 / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism; D053205:Pollen Tube / Q000378:metabolism; D011485:Protein Binding; D012260:Ribonucleases / Q000378:metabolism*; D060436:Self-Incompatibility in Flowering Plants; D032322:Solanum / Q000235:genetics* / Q000378:metabolism*
chemical_list: D000199:Actins; D020648:Peptide Elongation Factor 1; D010940:Plant Proteins; D012260:Ribonucleases