Background：Plastins are a family of actin-binding proteins that are conserved throughout eukaryote evolution and expressed in most tissues of higher eukaryotes. In humans, two ubiquitous plastin isoforms （L and T） have been identified. Plastin 1 （otherwise known as Fimbrin） is a third distinct plastin isoform which is specifically expressed at high levels in the small intestine. The L isoform is expressed only in hemopoietic cell lineages, while the T isoform has been found in all other normal cells of solid tissues that have replicative potential （fibroblasts, endothelial cells, epithelial cells, melanocytes, etc.）. The C-terminal 570 amino acids of the T-plastin and L-plastin proteins are 83％ identical. It contains a potential calcium-binding site near the N terminus. Alternate splicing results in multiple transcript variants.
