- Profilin in Phaseolus vulgaris is encoded by two genes (only one expressed in root nodules) but multiple isoforms are generated in vivo by phosphorylation on tyrosine residues. Guillén, G., Valdés-López, V., Noguez, R., Olivares, J., Rodríguez-Zapata, L.C., Pérez, H., Vidali, L., Villanueva, M.A., Sánchez, F. Plant J. (1999)