Protein Family Models

Na/H antiporters are key transporters in maintaining the pH of actively metabolising cells. The molecular mechanisms of antiport are unclear. These antiporters contain 10-12 transmembrane regions (M) at the amino-terminus and a large cytoplasmic region at the carboxyl terminus. The transmembrane regions M3-M12 share identity with other members of the family. The M6 and M7 regions are highly conserved. Thus, this is thought to be the region that is involved in the transport of sodium and hydrogen ions. The cytoplasmic region has little similarity throughout the family. [1]. 9537504. Comparative molecular analysis of Na+/H+ exchangers: a unified model for Na+/H+ antiport?. Dibrov P, Fliegel L;. FEBS Lett 1998;424:1-5. [2]. 9278382. Na+/H+ exchangers of mammalian cells. Orlowski J, Grinstein S;. J Biol Chem 1997;272:22373-22376. [3]. 9507001. Identification of a mitochondrial Na+/H+ exchanger. Numata M, Petrecca K, Lake N, Orlowski J;. J Biol Chem 1998;273:6951-6959. (from Pfam)

Date:

2024-10-16

The Monovalent Cation:Proton Antiporter-1 (CPA1) Family (TC 2.A.36) The CPA1 family is a large family of proteins derived from Gram-positive and Gram-negative bacteria, blue green bacteria, yeast, plants and animals. Transporters from eukaryotes have been functionally characterized, and all of these catalyze Na+:H+ exchange. Their primary physiological functions may be in (1) cytoplasmic pH regulation, extruding the H+ generated during metabolism, and (2) salt tolerance (in plants), due to Na+ uptake into vacuoles. This Hmm is specific for the bacterial members of this family.

Date:

2024-06-04

cation:proton antiporter functions in maintaining cation homeostasis and the pH of actively metabolizing cells; it may also be involved in regulating cell volume; similar to NhaP-type Na+/H+ or K+/H+ antiporter

Date:

2024-04-18