Profilin

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Profilin-1
Profilin-1
Ribbon model of profilin-1 (blue) bound to actin (green), according to PDB  1BTF
Properties of human protein
Mass / length primary structure 139 amino acids
Identifier
Gene name PFN1
External IDs

Profilin is a ubiquitous eukaryotic protein that u. a. is important for the formation of the so-called cytoskeleton in the cell . It has an important function for movement processes in the cell and in the transmission of signals between cells.

This 16  kDa large actin binding protein was described in 1976 as the first protein that does not bind to actin filaments, but to actin monomers. Initially, it was believed that the function of profilin was to prevent actin monomers from polymerizing at certain points in order to release them in response to a signal and to allow them to participate in the formation of actin filaments. Since 1995, however, several classes of proteins have been known (e.g. VASP, WASP, Formin ) that need profilin-actin complexes in order to allow actin filaments to polymerize at all, v. a. in areas of high physical activity. Profilin binds to such proteins by interacting with sequences rich in the amino acid proline . Profilin also has functions in the nucleus that little is known about, and binds to PIP2, a fat molecule found in biological membranes .

Profilin occurs in at least 3 isoforms in humans, some of which exist side by side in the same cell type and whose function is still little known. Profilins bind to at least 50 different proteins.

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