Spatial diffusivity and availability of intracellular calmodulin.

ABSTRACT: Calmodulin (CaM) is the major pathway that transduces intracellular Ca2+ increases to the activation of a wide variety of downstream signaling enzymes. CaM and its target proteins form an integrated signaling network believed to be tuned spatially and temporally to control CaM's ability to appropriately pass signaling events downstream. Here, we report the spatial diffusivity and availability of CaM labeled with enhanced green fluorescent protein (eGFP)-CaM, at basal and elevated Ca2+,quantified by the novel fluorescent techniques of raster image scanning spectroscopy and number and brightness analysis. Our results show that in basal Ca2+ conditions cytoplasmic eGFP-CaM diffuses at a rate of 10 microm(2)/s, twofold slower than the noninteracting tracer, eGFP, indicating that a significant

SUBMITTER: Sanabria H 

PROVIDER: S-EPMC2599858 | biostudies-literature | 2008 Dec

REPOSITORIES: biostudies-literature