Traffic ATPases

Based on experimental data and analysis of sequences available from the databases, we can conclude that different routes for the translocation of iron across the cytoplasmic membrane are possible in bacteria. They can mediate the importation of ferrous iron, and of ferric iron, both in its ionic form and coupled to siderophores or haem. Three of the transport systems represent members of the binding protein-dependent type (a subfamily of ABC transporters or traffic ATPases) (see Section 6.3.2). 

Phosphate Phosphate monoesters, Pst Uptake of phosphate Traffic ATPase pho reguion No... 

Giyceroi 3-phosphate UgpT Uptake of intact dissoived organic phosphorus Traffic ATPase pho reguion intraceiiuiar phosphate siows uptake No... 

Reits EA, Griekspoor AC, NeeQes J (2000a) How does TAP pump peptides Insights from DNA repair and traffic ATPases. Immunol Today 21 598-600... 

Metallochaperones (like ATOX 1) transfer copper to the site of synthesis of copper containing proteins (Rae et al., 1999 Huffman and O Halloran, 2002). The cytoplasmic copper chaperone ATOXl is required for copper delivery to ATP7B by direct protein-protein interaction (Hamza et al., 1999 Walker et al., 2002). ATP7B is abundantly expressed in hepatocytes and is localized in these cells to the late secretory pathway, predominantly the tran -Golgi network. With increasing intracellular copper concentrations, this ATPase traffics to a cytoplasmic vesicular compartment that distributes near the canaUcular membrane in polarized hepatocytes and... 

The 6 subunit of both the Na,K and H,K ATPases is necessary for targeting the complex from the endoplasmic reticulum to the plasma membrane. It also stabilizes a functional form of both the gastric H,K and Na,K ATPases. The region of assodation of the two subunits helps explain this functional assodation, and this assodation is apparently vital for stable membrane folding of the a subunit. The B subunit, however, can traffic to the plasma membrane in the absence of the a subunit. 

White SR, Lauring B. (2007) AAA-L ATPases achieving diversity of function with conserved machinery. Traffics, 1657-1667. 

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