Defective SLC34A2 does not cotransport HPO4(2-), 3Na+ from extracellular region to cytosol

Stable Identifier
R-HSA-5687585
Type
Reaction [transition]
Species
Homo sapiens
Compartment
Locations in the PathwayBrowser
General
SVG |   | PPTX  | SBGN
Click the image above or here to open this reaction in the Pathway Browser
The layout of this reaction may differ from that in the pathway view due to the constraints in pathway layout

The human gene SLC34A2 encodes NaPi-2b which is abundantly expressed in lung and to a lesser degree in epithelia of other tissues including small intestine, pancreas, prostate, and kidney. In the lung, SLC34A2 is expressed only in alveolar type II cells, which are responsible for surfactant production, so it is proposed that it uptakes liberated phosphate from the alveolar fluid for surfactant production. SLC34A2 cotransports divalent phosphate (HPO4(2-)) with three Na+ ions (electrogenic transport) from the extracellular region into alveolar type II cells. Defects in SLC34A2 can cause pulmonary alveolar microlithiasis (PALM; MIM:265100), a rare disease characterised by the deposition of calcium phosphate microliths (tiny, roundish corpuscles) throughout the lung. Most patients remain asymptomatic for years or decades, the disease following a long-term, progressive course resulting in slow deterioration of lung functions. Mutations leading to PALM include Q76*, G106R, V448*, K304* and Q486* (Corut et al. 2006, Yin et al. 2013, Proesmans et al. 2012).

Literature References
PubMed ID Title Journal Year
23164546 SLC34A2 Gene mutation of pulmonary alveolar microlithiasis: report of four cases and review of literatures

Yin, X, Wang, H, Wu, D, Zhao, G, Shao, J, Dai, Y

Respir Med 2013
16960801 Mutations in SLC34A2 cause pulmonary alveolar microlithiasis and are possibly associated with testicular microlithiasis

Corut, A, Senyigit, A, Ugur, SA, Altin, S, Ozcelik, U, Calisir, H, Yildirim, Z, Gocmen, A, Tolun, A

Am J Hum Genet 2006
22311166 Pulmonary alveolar microlithiasis: a case report and review of the literature

Proesmans, M, Boon, M, Verbeken, E, Ozcelik, U, Kiper, N, Van de Casseye, W, De Boeck, K

Eur. J. Pediatr. 2012
Participants
Participant Of
Catalyst Activity
Catalyst Activity
Title
sodium:phosphate symporter activity of SLC34A2 mutants [plasma membrane]
Physical Entity
Activity
Normal reaction
Disease
Name Identifier Synonyms
pulmonary alveolar microlithiasis 12117 pulmonary alveolar microlithiasis (disorder)
Authored
Reviewed
Created
Cite Us!