PKC isoform translocation in response to plasma.

Purified MKs were cultured in TPO either without plasma, with plasma, or with plasma and 100 ng/mL PMA for 48 hours; stained; and examined by immunofluorescent microscopy. PKC isoform α was labeled with FITC-conjugated specific antibodies (green), and nuclear DNA was labeled by propidium iodide (orange). (A) In the absence of plasma, PKCα was distributed throughout the cells with bright-green staining of the cell periphery. (B) In the presence of plasma, when MKs were forming proplatelets, PKCs were localized as a ring-like pattern (arrow) and peripheral staining was reduced. (C) Prolonged incubation with PMA down-modulated PKCα expression and prevented formation of this pattern of PKC distribution.