7W7R

High resolution structure of a fish aquaporin reveals a novel extracellular fold.

Summary for 7W7R

• Entry DOI: 10.2210/pdb7w7r/pdb
• Descriptor: Aquaporin 1 (1 entity in total)
• Functional Keywords: aquaporin, fish, anabas testudineus, pichia pastoris, transport protein, membrane protein
• Biological source: Anabas testudineus (climbing perch)
• Total number of polymer chains: 4
• Total formula weight: 102207.44

Authors

Zeng, J.,Schmitz, F.,Isaksson, S.,Glas, J.,Arbab, O.,Andersson, M.,Sundell, K.,Eriksson, L.,Swaminathan, K.,Tornroth-Horsefield, S.,Hedfalk, K. (deposition date: 2021-12-06, release date: 2022-10-12, Last modification date: 2023-11-29)

Primary citation

Zeng, J.,Schmitz, F.,Isaksson, S.,Glas, J.,Arbab, O.,Andersson, M.,Sundell, K.,Eriksson, L.A.,Swaminathan, K.,Tornroth-Horsefield, S.,Hedfalk, K.
High-resolution structure of a fish aquaporin reveals a novel extracellular fold.
Life Sci Alliance, 5:-, 2022

PubMed Abstract: Aquaporins are protein channels embedded in the lipid bilayer in cells from all organisms on earth that are crucial for water homeostasis. In fish, aquaporins are believed to be important for osmoregulation; however, the molecular mechanism behind this is poorly understood. Here, we present the first structural and functional characterization of a fish aquaporin; cpAQP1aa from the fresh water fish climbing perch (<i>Anabas testudineus</i>), a species that is of high osmoregulatory interest because of its ability to spend time in seawater and on land. These studies show that cpAQP1aa is a water-specific aquaporin with a unique fold on the extracellular side that results in a constriction region. Functional analysis combined with molecular dynamic simulations suggests that phosphorylation at two sites causes structural perturbations in this region that may have implications for channel gating from the extracellular side.

PubMed: 36229063
DOI: 10.26508/lsa.202201491

Experimental method

X-RAY DIFFRACTION (3.46 Å)