PMID- 10516278
OWN - NLM
STAT- MEDLINE
DCOM- 19991117
LR  - 20180925
IS  - 0002-9513 (Print)
IS  - 0002-9513 (Linking)
VI  - 277
IP  - 4
DP  - 1999 Oct
TI  - NaPO(4) cotransport type III (PiT1) expression in human embryonic kidney cells
      and regulation by PTH.
PG  - F543-51
LID - 10.1152/ajprenal.1999.277.4.F543 [doi]
AB  - The aim of the present study was to characterize the type(s) of NaPO(4)
      cotransporter expressed in the human renal cell line HEK-293 and its regulation
      by parathyroid hormone (PTH) in wild-type cells and in cells transfected by the
      PTH/PTH-related protein (PTHrP) receptor. The results showed that human embryonic
      kidney HEK-293 cells expressed NaPO(4) cotransporter type III (PiT1) mRNA and
      protein. In contrast, type I (NPT1) or II (NPT2) cotransporter mRNA were not
      expressed. Na(+)-dependent phosphate uptake followed a Michaelis-Menten model
      (apparent maximal transport rate and affinity constant: 23.32 +/- 0.69 nmol
      PO(4). mg protein(-1). 10 min(-1) and 0.147 +/- 0.014 mM KH(2)PO(4),
      respectively), was stimulated by phosphate deprivation (maximal increase 24.5 +/-
      0.8%, P < 0.001, after 15 h of phosphate deprivation), and was inhibited by
      increasing pH (3.6 +/- 0.2-fold decrease at pH 8.5, P < 0.0001). It was inhibited
      in a time- and concentration-dependent fashion by PTH in HEK-293 cells stably
      transfected by PTH/PTHrP receptors but not in parental HEK-293 cells. Maximal
      inhibition of Na(+)-dependent phosphate transport was observed at 30 min after
      the addition of 72 nM PTH-(1-34) (31.5 +/- 2.4% inhibition, P < 0.01). PTH
      inhibition of phosphate transport was maintained in phosphate-deprived cells and 
      reversed by both GF109203X (10(-6) M) or staurosporine (5.5 nM), two protein
      kinase C inhibitors. Na(+)-dependent phosphate uptake was also significantly
      inhibited by phorbol 12-myristate 13-acetate (20.9 +/- 3.9% inhibition, P <
      0.001) but not by dibutyril-cAMP (10(-4) M) or forskolin (50 microM). The
      physiological role played by type III NaPO(4) cotransport expression in the
      overall renal regulation of phosphate homeostasis remains to be established.
FAU - Fernandes, I
AU  - Fernandes I
AD  - Institut National de la Sante et de la Recherche Medicale, Faculte de Medecine
      Xavier Bichat, 75018 Paris, France.
FAU - Beliveau, R
AU  - Beliveau R
FAU - Friedlander, G
AU  - Friedlander G
FAU - Silve, C
AU  - Silve C
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Am J Physiol
JT  - The American journal of physiology
JID - 0370511
RN  - 0 (Carrier Proteins)
RN  - 0 (Parathyroid Hormone)
RN  - 0 (Phosphates)
RN  - 0 (SLC17A1 protein, human)
RN  - 0 (SLC17A2 protein, human)
RN  - 0 (SLC20A1 protein, human)
RN  - 0 (Sodium-Phosphate Cotransporter Proteins)
RN  - 0 (Sodium-Phosphate Cotransporter Proteins, Type I)
RN  - 0 (Sodium-Phosphate Cotransporter Proteins, Type III)
RN  - 0 (Symporters)
SB  - IM
MH  - Biological Transport/physiology
MH  - Carrier Proteins/*metabolism
MH  - Cell Line
MH  - Embryo, Mammalian/cytology/metabolism
MH  - Humans
MH  - Hydrogen-Ion Concentration
MH  - Kidney/*embryology
MH  - Kinetics
MH  - Parathyroid Hormone/*physiology
MH  - Phosphates/pharmacokinetics
MH  - Reverse Transcriptase Polymerase Chain Reaction
MH  - Sodium-Phosphate Cotransporter Proteins
MH  - Sodium-Phosphate Cotransporter Proteins, Type I
MH  - Sodium-Phosphate Cotransporter Proteins, Type III
MH  - *Symporters
MH  - Time Factors
EDAT- 1999/10/12 00:00
MHDA- 1999/10/12 00:01
CRDT- 1999/10/12 00:00
PHST- 1999/10/12 00:00 [pubmed]
PHST- 1999/10/12 00:01 [medline]
PHST- 1999/10/12 00:00 [entrez]
AID - 10.1152/ajprenal.1999.277.4.F543 [doi]
PST - ppublish
SO  - Am J Physiol. 1999 Oct;277(4):F543-51. doi: 10.1152/ajprenal.1999.277.4.F543.