Towards a structural and functional understanding of human aquaporin 9

• Aquaporins are membrane proteins that are present in all living organisms. Today thirteen mammalian aquaporins are identified and divided into two subgroups; aquaporins, which are strict water transporters and aquaglyceroporins that apart from water also transport glycerol, urea and other small uncharged solutes. One remarkable feature with these proteins is that they exclude protons. Aquaporins are expressed in a tissue specific manner and has showed to be involved in several diseases and are therefore potential drug targets. Human aquaporin 9 is an aquaglyceroporin that has the broadest specificity among the aquporins. hAQP9 transports arsenite, glycerol, small uncharged solutes and to some extent water. It is thought to be the main rout uptake of arsenite into the liver and might play a role in hepatic arsenic toxicity. In Asia drinking water are contaminated with arsenic and millions of people are exposed to toxic levels of arsenic every day that can result in an epidemic of hepatocellular carcinoma. Today no structure with atomic resolution is available from a mammalian aquaglyceroporin. Here we report that we have successfully over expressed and purified hAQP9 in the aim to purify pure protein for further crystallisation and structure determination. We also report of point mutations that reduce arsenite transport in our initial functional studies. The aim in this project is to understand how hAQP9 can discriminate between arsenite and glycerol.

Ämnesord

NATURVETENSKAP  -- Biologi -- Strukturbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Structural Biology (hsv//eng)

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

Nyckelord

aquaporin

transport

arsenite

glycerol

Publikations- och innehållstyp

vet (ämneskategori)

kon (ämneskategori)