Centrin is a component of the periocentriola lattice

Here, we use three polyclonal anticentrin antisera designated 08/28, 26/14-1, and 26/14-2 to further characterize the pericentriolar lattice of metazoan cells. all of these antibodies give an indistinguishable localization pattern that consists of a constellation of pericentrosomal spots. In QT6 cells these spots are few in number and closely associated with the centriolar region, whereas in PtK₂ cells they are more numerous and distributed further from the point of microtubule focus. In mitotic cells, centrin is localized to the spindle poles and spindle apparatus. We demonstrate here that the pericentriolar lattice of PtK₂ and QT6 cells is, in part, composed of proteins characterized by acidic pIs (4.4 to 5.4), low molecular mass (M_r 18 500-21 000), and calcium-binding; these attributes and the immunoreactivity of these proteins to anticentrin antibodies indicate that they are centrin isoforms of metazoan cells. Finally, we confirm our earlier observation that PtK₂ cells contain a centrin-related protein of M_r 165 000; QT6 cells also contain centrin-related proteins (M_r 64 000-165 000). We conclude that centrin is a component of the pericentriolar lattice of higher eukaryotic centrosomes.