FIGURE 3.

Anti-TKZ antibody immunofluorescent localization of the Z-repeat-Zq region of smooth muscle titin in cryosections of smooth muscle and cultured smooth muscle cells. A and B, cells in the smooth muscle layers of 10-μm-thick cryo cross-sections of adult porcine aorta were stained with anti-TKZ sm-titin primary antibody detected with Alexa Fluor 488-labeled secondary antibody (green) and 4′,6-diamidino-2-phenylindole to label the nuclei. The sm-titin antibody stained the cells in the smooth muscle layers but not the layers of elastic filaments between the layers of cells. C, anti-TKZ antibody staining of human coronary artery smooth muscle cells and rat aorta smooth muscle A7r5 cells were grown for 4 days on a polyelectrolyte multilayer (Nafion®)-coated coverslip. Growth on Nafion induces the cells to become contractile. The anti-smtitin antibody (D) yields linear, punctate patterns of labeling aligned with but not completely overlapping rhodamine phalloidin-stained actin filaments (E). F, merged image of D and E. Bar in A, 500 μm; bar in B, 250 μm; bars in C–F, 20 μm.