Caenorhabditis elegans expresses three functional profilins in a tissue-specific manner

• Published in: Cell motility and the cytoskeleton Vol. 63; no. 1; p. 14
• Main Authors: Polet, D, Lambrechts, A, Ono, K, Mah, A, Peelman, F, Vandekerckhove, J, Baillie, D L, Ampe, C, Ono, S
• Format: Journal Article
• Language: English
• Published: United States 01.01.2006
• Subjects: Actin Cytoskeleton - drug effects; Actins - chemistry; Animals; Caenorhabditis elegans - embryology; Caenorhabditis elegans - metabolism; Cell Movement; Cell Survival; Embryo, Nonmammalian - metabolism; In Vitro Techniques; Models, Biological; Molecular Sequence Data; Organ Specificity; Peptides - chemistry; Profilins - genetics; Profilins - metabolism; Profilins - pharmacology; Profilins - physiology; Proline - chemistry; Protein Binding; Protein Isoforms - metabolism; Rabbits
• ISSN: 0886-1544; 1097-0169
• DOI: 10.1002/cm.20102

Profilins are actin binding proteins, which also interact with polyphosphoinositides and proline-rich ligands. On the basis of the genome sequence, three diverse profilin homologues (PFN) are predicted to exist in Caenorhabditis elegans. We show that all three isoforms PFN-1, PFN-2, and PFN-3 are expressed in vivo and biochemical studies indicate they bind actin and influence actin dynamics in a similar manner. In addition, they bind poly(L-proline) and phosphatidylinositol 4,5-bisphosphate micelles. PFN-1 is essential whereas PFN-2 and PFN-3 are nonessential. Immunostainings revealed different expression patterns for the profilin isoforms. In embryos, PFN-1 localizes in the cytoplasm and to the cell-cell contacts at the early stages, and in the nerve ring during later stages. During late embryogenesis, expression of PFN-3 was specifically detected in body wall muscle cells. In adult worms, PFN-1 is expressed in the neurons, the vulva, and the somatic gonad, PFN-2 in the intestinal wall, the spermatheca, and the pharynx, and PFN-3 localizes in a striking dot-like fashion in body wall muscle. Thus the model organism Caenorhabditis elegans expresses three profilin isoforms and is the first invertebrate animal with tissue-specific profilin expression.