Purification, Characterization, and cDNA Cloning of Profilin from Phaseolus vulgaris

Abstract

Profilin from common bean (Phaseolus vulgaris 1.) was purified to homogeneity by poly-i-Pro affinity chromatography and gel filtration. The hypocotyl and symbiotic root nodule protein was detected as a single isoform with a 14.4-kD molecular mass and an isoelectric point of 5.3. Partia1 amino acid and DNA sequencing of a full-length cDNA clone confirmed its identity as profilin. An antibody generated against the purified protein binds to a protein with the same molecular mass in leaves and nodules. Immunolocalization of the protein showed a diffuse distribution in the cytoplasm of hypocotyls and nodules but enhanced staining at the vascular bundles. The strong identity of the sequence among the profilins of birch, maize, and bean suggests that it may play an important role in the signal transduction mechanism of plant cells and plantbacterial symbioses.

The Arabidopsis Profilin Gene Family (Evidence for an Ancient Split between Constitutive and Pollen-Specific Profilin Genes)

“…PRFl was constitutively expressed in most organs; PRFZ, PRF2, and PRF3 were each identified in both flower and leaf (not shown) cDNA libraries; and Pvu was expressed in leaves and roots (Vidali et al, 1995). This second clade (Fig.…”

“…Profilin cDNAs expressed primarily in pollen in maize (Zea mays L.) and tobacco (Nicotiana tabacum) (Staiger et al, 1993;Mittermann et al, 1995) and in the leaves and root nodules of beans (Phaseolus vulgaris) (Vidali et al, 1995) have been partially characterized. Other monocot and dicot profilin cDNAs have been isolated from pollen libraries , and profilin proteins have been isolated from vegetative organs (Ebner et al, 1991;Vallier et al, 1992), but the specificity of their expression patterns and the functional significance of having multiple plant profilins are not known.…”

Profilin Plays a Role in Cell Elongation, Cell Shape Maintenance, and Flowering in Arabidopsis

“…PFNs have been identified and characterized from several plant species including maize and tomato pollen (Staiger et al, 1993;Yu et al, 1998), tobacco (Mittermann et al, 1995), leaves and root nodules of Phaseolus vulgaris (Vidali et al, 1995;Guillen et al, 1999), and Arabidopsis (Christensen et al, 1996;Huang et al, 1996). Plant PFNs have been shown to bind plant and animal actin in vitro Giehl et al, 1994;Ruhlandt et al, 1995;Rothkegel et al, 1996).…”

Differential Immune-Reactivity and Subcellular Distribution Reveal the Multifunctional Character of Profilin in Pollen as Major Effect of Sequences Polymorphism

“…Profilin has also been found in generative and vegetative nuclei of Ledebouria socialis pollen (Hess and Valenta 1997), the nuclei of Phaseolus vulgaris cells (Vidali et al 1995) and Arabidopsis thaliana and maize root hairs (Braun et al 1999, Baluska et al 2001). Microinjection of a fluorescently labeled birch profilin in Micrasterias denticulata also shows an accumulation of profilin in the nucleus (Holzinger et al 1997).…”