High impact information on SLC9A7

• Thus, NHE7 displays unique functional and pharmacological properties and may play an important role in maintaining cation homeostasis of this important organelle [1].
• Here, we describe the cloning of a novel gene (NHE7) in humans that is homologous to Na+/H+ exchangers, is ubiquitously expressed, and localizes predominantly to the trans-Golgi network [1].
• The activity of NHE7 was also found to be relatively insensitive to inhibition by amiloride but could be antagonized by the analogue benzamil and the unrelated compound quinine [1].
• Conversely, a GFP-tagged TM2-TM3 construct of SCAMP2 interacted with NHE7, but also led to the redistribution of NHE7 to dispersed vesicular structures [2].
• Secretory carrier membrane proteins interact and regulate trafficking of the organellar (Na+,K+)/H+ exchanger NHE7 [2].

Biological context of SLC9A7

• To gain insight into these processes, yeast two-hybrid methodology was used to screen a human brain cDNA library for proteins that interact with the cytoplasmic C-terminus of NHE7 [2].
• Endocytosis of NHE7 was efficiently inhibited by pharmacological maneuvers that block clathrin-dependent endocytosis, whereas dominant-negative caveolin mutants or methyl beta-cyclodextrin did not affect NHE7-internalization [3].

Anatomical context of SLC9A7

• Thus, NHE7 associates with both caveolae/lipid rafts and non-caveolae/lipid raft, and the two pools likely exhibit separate dynamics [3].
• NHE7 was identified as the first mammalian organelle-membrane type (Na(+), K(+))/H(+) exchanger that may contribute to the ion homeostasis in the trans-Golgi network (TGN) and endosomes [3].

Associations of SLC9A7 with chemical compounds

• NHE7 is partly associated with caveolae/lipid raft fractions, and heterologous expression of caveolin dominant-negative mutants as well as cholesterol depriving drugs diminished such associations [3].

Physical interactions of SLC9A7

• Biochemical analyses indicated that the C-terminal cytoplasmic tail of NHE7 bound preferentially to a highly conserved cytoplasmic loop between the second and the third transmembrane segments (TM2-TM3 loop) of SCAMP2 [2].

Other interactions of SLC9A7

• The majority of the NHE7-SCAMP complexes accumulated at the TGN, but a minor fraction also resided in recycling vesicles [2].
• All, except NHE-6 and NHE-7, which are located intracellularly, are restricted to the sarcolemmal membrane [4].

References