Akuaporin 2 merupakan satu-satunya akuaporin yang diregulasi oleh vasopresin.[4]
Fungsi dasar akuaporin 2 adalah untuk mereabsorbsi air dari urin ketika air tersebut dibuang dari darah oleh ginjal. Akuaporin 2 ditemukan pada sel epitel ginjal dan biasanya dorman di dalam membran vesikel intraseluler. Ketika dibutuhkan, vasopresin berikatan dengan reseptor vasopresin permukaan sel yang mengaktifkan jalur pensinyalan dan menyebabkan vesikel yang memuat akuaporin 2 untuk berfusi dengan membran plasma sehingga akuaporin 2 dapat digunakan oleh sel.[5]
Regulasi jangka pendek (menit) melalui lalu lintas vesikel AQP2 ke wilayah apikal yang kemudian berfusi dengan membran plasma apikal.
Regulasi jangka panjang (hari) melalui peningkatan ekspresi gen AQP2.
Akuaporin ini juga diregulasi oleh asupan makanan. Berpuasa mengurangi ekspresi akuaporin ini yang tak bergantung vasopresin.
Signifikansi klinis
Mutasi saluran ini diasosiasikan dengan diabetes insipidus nefrogenik, yang dapat berupa dominan atau resesif autosomal. Mutasi pada reseptor vasopresin menyebabkan fenotipe terpaut-X serupa.
Litium, sering digunakan untuk mengobati gangguan bipolar, dapat menyebabkan diabetes insipidus perolehan (ditandai dengan ekskresi urin encer bervolume besar) dengan menurunkan ekspresi gen AQP2.
↑"Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
↑"Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
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↑Lodish, Harvey; Berk, Arnold; Kaiser, Chris A.; Krieger, Monty; Scott, Matthew P.; Bretscher, Anthony; Ploegh, Hidde; Matsudaira, Paul (2008). Molecular Cell Biology (Edisi 6th). New York: Freeman. hlm.445. ISBN978-0-7167-7601-7.
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