Fig. 7.

Thbs3 enhances secretory pathway activity but reduces membrane integrins. a Time course of intracellular trafficking fluorescence changes in cultured neonatal ventricular cardiomyocytes (NRVMs) infected with a GalNac-T2-RFP baculovirus and the indicated adenoviruses. The data show a quantitative time course of GalNac-T2-RFP recovery in the Golgi network after FRAP to measure ER-to-Golgi vesicular trafficking. *P < 0.05 versus Adβgal infected cells. b Quantitative time course of loss of VSVG-eGFP fluorescence in the Golgi after iFRAP as a measurement for Golgi-to-membrane (Golgi exit) vesicular trafficking. *P < 0.05 versus Adβgal infected cells. Statistical analysis was performed using two-way ANOVA and Turkey multiple comparisons test. c Western blots for ECM proteins using heart extracellular matrix extracts from tTA, Thbs3 DTG and Thbs4 DTG mice at baseline or with TAC stimulation. A silver-stained gel is shown with a non-specific (n.s.) band as a loading control. d, e Quantitative time-course of the loss of α5 integrin-GFP fluorescence at the Golgi after iFRAP as a measure of Golgi-to-plasma membrane vesicular trafficking of α5 integrin. The data were generated by iFRAP of α5 integrin-GFP from COS-7 cells d transfected with the plasmids harboring the cDNAs shown or e treated with recombinant Thbs3 or Thbs4 proteins, or bovine serum albumin (BSA) as a control. *P < 0.05 versus Adβgal transfected cells; #<0.05 versus Thbs3 transfected cells. Statistical analysis was performed using two-way ANOVA and Turkey multiple comparisons test. Results were summed from four independent experiments and error bars are +/− standard error of the mean