Like AQP1, aquaporin-2 (AQP2) is a homotetrameric water channel, and protein kinase A is involved in its vasopressin-induced translocation from intracellular vesicle to the apical membrane.

So I wish to raise the following three questions:

1. Is Raf Ser/Thr kinase also involved in its phosphorylation?

2. Is there any other motor protein involved in AQP2 shuttling than myosins (see here and here.) or dynein?

3. If such motor protein exists, can we observe its motion using AFM in solution?