AAAP family explained

Symbol:	AAAP
Amino Acid/Auxin Permease Family
Pfam:	PF01490
Pfam Clan:	CL0062
Interpro:	IPR013057
Tcdb:	2.A.18

The Amino Acid/Auxin Permease (AAAP) Family (TC# 2.A.18) is a family of secondary carrier proteins, a member of the APC Superfamily that includes hundreds of proteins from plants, animals, fungi and lower eukaryotes. Six AAAPs in A. thaliana are well characterized and transport neutral and charged amino acids with varying specificities and affinities.^{[1] [2]}

Function

Among animal AAAP family members are numerous growth regulating System A and System N isoforms, each exhibiting distinctive tissue and subcellular localizations. The different isoforms also exhibit different relative affinities for the amino acid substrates. Some catalyze H⁺ antiport and can function bidirectionally. Since Systems A are electrogenic which Systems N are not, the amino acid:cation stoichiometries may differ.^{[2] [3] [4] [5]}

Notes and References

1. Fischer WN, Loo DD, Koch W, Ludewig U, Boorer KJ, Tegeder M, Rentsch D, Wright EM, Frommer WB . Low and high affinity amino acid H+-cotransporters for cellular import of neutral and charged amino acids . The Plant Journal . 29 . 6 . 717–731 . March 2002 . 12148530 . 10.1046/j.1365-313x.2002.01248.x . free .
2. Web site: Saier Jr MH . 2.A.18 The Amino Acid/Auxin Permease (AAAP) Family. Transporter Classification Database. Saier Lab Bioinformatics Group.
3. Chaudhry FA, Krizaj D, Larsson P, Reimer RJ, Wreden C, Storm-Mathisen J, Copenhagen D, Kavanaugh M, Edwards RH . Coupled and uncoupled proton movement by amino acid transport system N . The EMBO Journal . 20 . 24 . 7041–7051 . December 2001 . 11742981 . 125789 . 10.1093/emboj/20.24.7041 .
4. Chaudhry FA, Schmitz D, Reimer RJ, Larsson P, Gray AT, Nicoll R, Kavanaugh M, Edwards RH . Glutamine uptake by neurons: interaction of protons with system a transporters . The Journal of Neuroscience . 22 . 1 . 62–72 . January 2002 . 11756489 . 6757603 . 10.1523/JNEUROSCI.22-01-00062.2002 .
5. Varoqui H, Zhu H, Yao D, Ming H, Erickson JD . Cloning and functional identification of a neuronal glutamine transporter . The Journal of Biological Chemistry . 275 . 6 . 4049–4054 . February 2000 . 10660562 . 10.1074/jbc.275.6.4049 . free .