Integrin signaling modulates AQP2 trafficking via Arg-Gly-Asp (RGD) motif.
2011
Aquaporin-2(AQP2) increases the water permeability of renal collecting ducts in response to
vasopressin.
Vasopressinstimulation is accompanied by a profound remodeling of actin cytoskeleton whose dynamics are regulated by crosstalk between
intracellularand extracellular signals. Here, we report that AQP2 contains a conserved RGD domain in its external C-loop. Co-immunoprecipitation experiments demonstrated that AQP2 binds integrin β1 in renal tissue and in MCD4 cells. To investigate the role of this interaction on AQP2 trafficking, cells were exposed to synthetic RGD-containing peptides, GRGDNP or GRGDSP, able to bind certain integrins. Incubation with these peptides increased the membrane expression of AQP2 in the absence of hormonal stimulation as assessed by confocal analysis and cell surface
biotinylation. To identify the signals underlying the effects of peptides on AQP2 trafficking, some possible
intracellularmessengers were evaluated. Exposure of MCD4 cells to GRGDNP increased
intracellularcAMP as assessed by FRET studies while GRGDSP increased
intracellularcalcium concentration. Taken together, these data propose integrins as new players controlling the cellular localization of AQP2, via two distinct signal transduction pathways dependent on cAMP and calcium respectively.
Keywords:
-
Correction
-
Source
-
Cite
-
Save
59
References
38
Citations
NaN
KQI