Table 1.
SLC 9 family of Na+/H+ exchangersc. For detailed information about the SLC gene tables, please visit: http://www.bioparadigms.org.
| Human gene name |
Protein name |
CPA subfamily |
Number of aa.a |
Substrates | Human disease | Knock-out mice phenotypes |
|---|---|---|---|---|---|---|
| SLC9A1 | NHE1 | CPA1 | 815 | Na+, Li+, H+, NH4+ | Ataxia, growth retardation, seizures, slow-wave epilepsy, increased neuronal excitability, resistant to cardiac ischemia–reperfusion injury and premature death | |
| SLC9A2 | NHE2 | CPA1 | 812 | Na+, Li+ H+, NH4+ | Reduced viability of gastric parietal cells, hypochlorhydria, Increased renal renin content, impaired recovery of intestinal barrier function | |
| SLC9A3 | NHE3 | CPA1 | 834 | Na+, Li+, H+, NH4+ | Congenital Na diarrhea; Sudden infant death syndrome | Mild-diarrhea, acidosis, impaired acid–base balance and Na-fluid volume homeostasis in kidney and intestine. Spontaneous distal colitis due to luminal bacteria |
| SLC9A4 | NHE4 | CPA1 | 798 | Na+, Li+(?), H+, NH4+ | Stomach inflammation, hypochlorhydria, gastric necrosis. Defective in ammonium/ammonia absorption in renal thick ascending limb | |
| SLC9A5 | NHE5 | CPA1 | 896 | Na+, Li+, H+, NH4+ (?) | ||
| SLC9A6 | NHE6 | CPA1 | 701 (v1) b669(v2) 649(v3) | Na+, K+, H+ | X-linked Mental Retardation (Angelman Syndrome and Christianson Subtype). Epilepsy and ataxia | Hyper-reactivity, increased susceptibility to pharmacologically induced seizures |
| SLC9A7 | NHE7 | CPA1 | 725 | Na+, K+, Li+, H+, NH4+ (?) | ||
| SLC9A8 | NHE8 | CPA1 | 581 | Na+, K+, H+ | ||
| SLC9A9 | NHE9 | CPA1 | 645 | Na+, K+, H+ | Familial Autism; Attention Deficit Hyperactivity Disorder | |
| SLC9B1 | NHA1 (NHEDC1) | CPA2 | 515 (v1) 475(v2) | |||
| SLC9B2 | NHA2 (NHEDC2) | CPA2 | 537 | Na+, Li+ | Essential hypertension (?) | |
| SLC9C1 | Sperm-NHE | NaT-DC | 1177 (v1) 1129(v2) | Na+, H+ | Infertile male, asthenozoospermia | |
| SLC9C2 | NaT-DC | 1124 |
a
Human
b
v = variant
c
Human SLC9 family is a subgroup of the monovalent cation proton antiporter (CPA) superfamily as described by Brett et al. (2005a,b). The human SLC9A is part of CPA1 family and the human SLC9B is part of CPA2 family. The human SLC9C is weakly associated with NaT-DC (Na-transporting carboxylic acid decarboxylase) family.