Аннотация:Here we investigated the DU145 cell line by immunofluorescence using antibodies against the full‐length AAT molecule and its C‐terminus. Both antibodies reveal protein accumulation in the nucleus, predominantly in euchromatin and the interchromosomal space, but not in the nucleoli and heterochromatin. When cells progress into mitosis, the fraction of AAT detected exclusively by anti‐C‐terminal antibodies arises as a bona fide component of the outer kinetochore, that can be visualized after cell permeabilization. The full‐length AAT anchors to the mitotic spindle and spindle poles. We have found that this AAT intracellular distribution is RNA‐dependent, so the non‐secretory AAT is the RNA‐ or RNP‐binding protein.