Characterization of transport mechanisms and determinants critical for Na+-dependent Pi symport of the PiT family paralogs human PiT1 and PiT2.

@article{Bttger2006CharacterizationOT,
  title={Characterization of transport mechanisms and determinants critical for Na+-dependent Pi symport of the PiT family paralogs human PiT1 and PiT2.},
  author={Pernille B{\o}ttger and Susanne E. Hede and Morten Grunnet and Boy. Hoyer and Dan Arne Klaerke and Lene Juul Pedersen},
  journal={American journal of physiology. Cell physiology},
  year={2006},
  volume={291 6},
  pages={
          C1377-87
        }
}
The general phosphate need in mammalian cells is accommodated by members of the P(i) transport (PiT) family (SLC20), which use either Na(+) or H(+) to mediate inorganic phosphate (P(i)) symport. The mammalian PiT paralogs PiT1 and PiT2 are Na(+)-dependent P(i) (NaP(i)) transporters and are exploited by a group of retroviruses for cell entry. Human PiT1 and PiT2 were characterized by expression in Xenopus laevis oocytes with (32)P(i) as a traceable P(i) source. For PiT1, the Michaelis-Menten… 
Deciphering PiT transport kinetics and substrate specificity using electrophysiology and flux measurements.
TLDR
On the basis of the kinetics of substrate interdependence, an ordered binding scheme of Na(+):H(2)PO(4)(-):Na(+) is proposed and changes in oocyte surface pH were consistent with transport of monovalent P(i).
Mapping of the minimal inorganic phosphate transporting unit of human PiT2 suggests a structure universal to PiT-related proteins from all kingdoms of life
TLDR
The results suggest that the overall structure of the Pi-transporting unit of thePiT family proteins has remained unchanged during evolution.
Phosphate transporters: a tale of two solute carrier families.
TLDR
This review focuses on recent advances in the characterization of the transport kinetics, structure-function relationships, and physiological implications of having two distinct Na+/P(i) cotransporter families.
An Externally Accessible Linker Region in the Sodium-Coupled Phosphate Transporter PiT-1 (SLC20A1) is Important for Transport Function
TLDR
The external accessibility of a linker region in PiT-1 was confirmed and sites were identified that determine substrate selectivity and transport function and underscoring the importance of this linker in defining Pi T-1 transport characteristics.
Identification of a Novel Function of PiT1 Critical for Cell Proliferation and Independent of Its Phosphate Transport Activity*♦
TLDR
This study is the first to describe the effects of a Pi transporter in cell proliferation, tumor growth, and cell signaling and shows that modulation of cell proliferation by PiT1 is independent from its transport function because the proliferation ofPiT1-depleted cells can be rescued by non-transporting PiT2 mutants.
Phosphate transporters and their function.
TLDR
Plasma phosphate concentration is maintained within a relatively narrow range by control of renal reabsorption of filtered inorganic phosphate by controlling the transport mechanism of the two kidney-specific SLC34 proteins and of the ubiquitously expressed SLC20 protein (PiT-2).
Evidence for PiT-Type (SLC20) and NaPi-II-Type (SLC34) Transporters in the Rat Choroid Plexus
TLDR
The results indicate that a PiT-type transporter is responsible for Pi transport in the brain choroid plexus and indicate that NaPi-IIb is potentially present in the CP, indicating that the secondary-active, CP transport of phosphate out of the CSF may involve more than one family of solute carrier transporters.
Phosphate transporters of the SLC 20 and SLC 34 families
TLDR
This review summarizes the current knowledge of SLC20 and SLC34 proteins in terms of their basic molecular characteristics, physiological roles, known pathophysiology and pharmacology.
...
...

References

SHOWING 1-10 OF 47 REFERENCES
Two Highly Conserved Glutamate Residues Critical for Type III Sodium-dependent Phosphate Transport Revealed by Uncoupling Transport Function from Retroviral Receptor Function* 210
TLDR
It is shown that it is possible to uncouple transport and receptor functions of a type III NaPicotransporter and thus exploit the retroviral receptor function as a control for proper processing and folding of mutant proteins.
Cloning and characterization of a type III Na-dependent phosphate cotransporter from mouse intestine.
TLDR
The presence of mPit-2 in the mouse intestine and its unique transport characteristics suggest that multiple Na-dependent cotransporters may contribute to phosphate absorption in the mammalian small intestine.
Characterization of PitA and PitB fromEscherichia coli
TLDR
Evidence is presented that pitB encodes a functional P(i) transporter that may be repressed at low P( i) levels by the pho regulon, and the apparent K(m) of PitB decreased with increased levels of protein expression, suggesting that there is also regulation of the PitB protein.
Transmembrane Topology of PiT-2, a Phosphate Transporter-Retrovirus Receptor
TLDR
A model in which PiT-2 has 12 transmembrane domains and extracellular N- and C-terminal extremities is proposed, which differs significantly from previous predictions about PiT -2 topology, and may be useful for further investigations of Pi T-2 interactions with other proteins and for the understanding of Pit-2 transporter and virus receptor functions.
NaPO4 cotransport type III (PiT1) expression in human embryonic kidney cells and regulation by PTH.
TLDR
The results showed that human embryonic kidney HEK-293 cells expressed NaPO4 cotransporter type III (PiT1) mRNA and protein, in contrast, type I (NPT1) or II(NPT2) cotranporter mRNA were not expressed, and the physiological role played by type III Na PO4 cOTransport expression in the overall renal regulation of phosphate homeostasis remains to be established.
Molecular cloning and hormonal regulation of PiT-1, a sodium-dependent phosphate cotransporter from rat parathyroid glands.
TLDR
Rat PiT-1 may contribute to the effects of Pi and vitamin D on parathyroid function by possessing Na+-dependent Pi cotransport activity, which is widely distributed in rat tissues and is most abundant in brain, bone and small intestine.
Identification and characterization of a widely expressed phosphate transporter/retrovirus receptor family.
TLDR
The cell-surface receptors for gibbon ape leukemia virus and rat amphotropic virus were recently demonstrated to serve normal cellular functions as sodium-dependent phosphate transporters, establishing them as members of a new family of phosphatetransporters which may play a major role in phosphate uptake in a wide variety of cell types.
Evolutionary and experimental analyses of inorganic phosphate transporter PiT family reveals two related signature sequences harboring highly conserved aspartic acids critical for sodium‐dependent phosphate transport function of human PiT2
The mammalian members of the inorganic phosphate (Pi) transporter (PiT) family, the type III sodium‐dependent phosphate (NaPi) transporters PiT1 and PiT2, have been assigned housekeeping Pi transport
Evidence for the transport of zinc(II) ions via the pit inorganic phosphate transport system in Escherichia coli.
A locus involved in zinc(II) uptake in Escherichia coli K-12 was identified through the generation of a zinc(II)-resistant mutant by transposon (Tn10dCam) mutagenesis. The mutation was located within
...
...