Table 6. Transport mechanism and energetics in RhCG proteins^*.

Mechanism*	Supporting evidence	Possible energetics	References
7&	Human RhCG (formerly RhGK) - Yeast resistance to MeA toxicity, -Ammonium excretion essay	pH gradient dependent	[100]
8	Human RhCG Electrogenic transport Current depend on [NH3]	Δψ dependent	[101]
5&	Human RhCG - ammonium pulse associated with alkalanisation of cell/lipososme/erythrocyte vesicles expressing RhBC - pHi acidification when cell loaded with ammonium were pulse with ammornium-free buffer	NH3 chemical gradient	[73,102]
7	Mouse RhCG - Electroneutral transport of MeA in oocyte - Stimulated by outwardly pH gradient.	pH gradient dependent Δψ independent	[98]
5	Human RhCG -Electroneutral transport of ammonium and MeA in oocyte -Increase flux when increase external pH -MeA transport essay in yeast	NH3 chemical gradient	[71]
5	Human RhCG - Alkalinisation inside liposomes containing purified RhCG after an ammonium pulse	NH3 chemical gradient	[14]
5	Human RhCG - Oocyte pHs fall after ammonium pulse on oocyte	Potentially Δψ NH4+ electrochemical gradient	[86]
5	Mouse RhCG -pHs decrease upon ammonium pulse, but not with MeA	NH3 chemical gradient	[87]
4	Human RhCG -Molecular and quantum mechanical calculations	Potentially Δψ independent or NH4+ electrochemical gradient	[103]

^*Mechanism: 3 - NH₄⁺/H+ symport, 4 - NH₄⁺ deprotonation following by NH₃ transport only, 5 - NH₃ uniport, 7 - NH₄⁺/H⁺ antiport, 8 - Transport of both NH₃ and NH₄⁺, &- the activity may be bidirectional activity.