Twinfilin 2 (TWF2)

PTK9L was phosphorylated by PKC-zeta, but not significantly by other PKC isoenzymes. It was also phosphorylated by casein kinase II and most effectively by the tyrosine kinase SRC. In accordance with its potential ATP-binding site, PTK9L was able to bind ATP.The deduced 349-amino acid protein has a calculated molecular mass of 39.5 kD. PTK9L contains a consensus sequence for actin-depolymerizing proteins and 2 ATP-binding motifs. It shares 64% amino acid identity with the human A6 protein (PTK9), 97% identity with mouse Ptk9l, 34% identity with C. elegans A6, and 26% identity with yeast twinfilin. RT-PCR and Western blot analysis detected PTK9L in all human and mouse tissues and cells tested. Immunofluorescence localization revealed spotty accumulation of PTK9L in the cytoplasm close to nuclei.