Tyrosine phosphatase PTP1B interacts with TRPV6 in vivo and plays a role in TRPV6-mediated calcium influx in HEK293 cells.
This study investigates the role of tyrosine phosphorylation and dephosphorylation in the regulation of the Ca(2+) permeant TRPV6 channel. HEK293 cells co-transfected with TRPV6 and the tyrosine phosphatase PTP1B show a constitutive Ca(2+) entry which was independent of tyrosine phosphorylation under resting conditions. Following depletion of intracellular Ca(2+) stores, TRPV6-mediated Ca(2+) entry could be increased in the presence of a tyrosine phosphatase inhibitor (bis-(N,N-dimethyl-hydroxamido) hydroxo-vanadate; DMHV). Inhibition of Src-kinases completely abolished DMHV-induced increase in TRPV6-mediated Ca(2+) influx. Co-transfection with Src led to tyrosine phosphorylation of TRPV6 which could be dephosphorylated by PTP1B. In vivo interaction of TRPV6 with PTP1B was visualized using the bimolecular fluorescence complementation (BiFC) method and proved by co-immunoprecipitation of both proteins. These data indicate that tyrosine phosphorylation is involved in the regulation of the TRPV6 channel protein.
Sternfeld
Lutz
L
Physiological Institute, University of the Saarland, Germany.
Krause
Elmar
E
Schmid
Andreas
A
Anderie
Ines
I
Latas
Anna
A
Al-Shaldi
Hajaj
H
Köhl
Andreas
A
Evers
Katrin
K
Hofer
Hans Werner
HW
Schulz
Irene
I
D000818:Animals; D015153:Blotting, Western; D002118:Calcium / Q000737:chemistry / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism*; D002460:Cell Line; D003001:Cloning, Molecular; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D047468:Immunoprecipitation; D018715:Microscopy, Video; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry / Q000502:physiology*; D051381:Rats; D013050:Spectrometry, Fluorescence; D050916:TRPV Cation Channels; D013997:Time Factors; D014162:Transfection; D014443:Tyrosine / Q000737:chemistry / Q000378:metabolism; D014638:Vanadates / Q000494:pharmacology; D019061:src-Family Kinases / Q000378:metabolism
D015220:Calcium Channels; D050916:TRPV Cation Channels; C120776:TRPV6 channel; C402001:bis(N,N-dimethylhydroxamido)hydroxooxovanadate; D049452:Green Fluorescent Proteins; D014638:Vanadates; D014443:Tyrosine; D019061:src-Family Kinases; C516607:PTPN1 protein, human; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases; C516610:Ptpn1 protein, rat; D002118:Calcium