scholarly journals Molecular cloning and immunolocalization of a novel vertebrate trp homologue from Xenopus

1999 ◽  
Vol 340 (3) ◽  
pp. 593-599 ◽  
Author(s):  
Laura K. BOBANOVIĆ ◽  
Mika LAINE ◽  
Carl C. H. PETERSEN ◽  
Deborah L. BENNETT ◽  
Michael J. BERRIDGE ◽  
...  
Keyword(s):  
Antisense Oligonucleotides ◽  
Xenopus Oocytes ◽  
Transient Receptor Potential ◽  
Polyclonal Antibodies ◽  
Sequence Similarity ◽  
Receptor Potential ◽  
Calcium Entry ◽  
Capacitative Calcium Entry ◽  
Sequence Structure ◽  
Transient Receptor

We report the sequence, structure and distribution of a novel transient receptor potential (trp) homologue from Xenopus, Xtrp, determined by screening an oocyte cDNA library. On the basis of sequence similarity and predicted structure, Xtrp appears to be a homologue of mammalian trp1 proteins. Two polyclonal antibodies raised against distinct regions of the Xtrp sequence revealed Xtrp expression in various Xenopus tissues, and the localization of Xtrp at the plasma membrane of Xenopus oocytes and HeLa cells. Since capacitative calcium entry into Xenopus oocytes has been shown previously to be substantially inhibited by trp1 antisense oligonucleotides [Tomita, Kaneko, Funayama, Kondo, Satoh and Akaike (1998) Neurosci. Lett. 248, 195-198] we suggest that Xtrp may underlie capacitative calcium entry in Xenopus tissues.

Expression and relative abundance of short transient receptor potential channels in the rat renal microcirculation

2004 ◽  
Vol 286 (3) ◽  
pp. F546-F551 ◽  
Author(s):  
Carie S. Facemire ◽  
Peter J. Mohler ◽  
William J. Arendshorst
Keyword(s):  
Relative Abundance ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Cell Types ◽  
Calcium Entry ◽  
Transient Receptor Potential Channels ◽  
Trpc Channels ◽  
Renal Microcirculation ◽  
Resistance Vessels ◽  
Transient Receptor

In the resistance vessels of the renal microcirculation, store- and/or receptor-operated calcium entry contribute to the rise in vascular smooth muscle cell (VSMC) intracellular calcium concentration in response to vasoconstrictor hormones. Short transient receptor potential (TRPC) channels are widely expressed in mammalian tissues and are proposed mediators of voltage-independent cation entry in multiple cell types, including VSMCs. The seven members of the TRPC gene family (TRPC1-7) encode subunit proteins that are thought to form homo- and heterotetrameric channels that are differentially regulated depending on their subunit composition. In the present study, we demonstrate the relative abundance of TRPC mRNA and protein in freshly isolated rat renal resistance vessels, glomeruli, and aorta. TRPC1, 3, 4, 5, and 6 mRNA and protein were detected in both renal resistance vessels and aorta, whereas TRPC2 and TRPC7 mRNA were not expressed. TRPC1, 3, 5, and 6 protein was present in glomeruli. TRPC3 and TRPC6 protein levels were significantly greater in the renal resistance vessels, about six- to eightfold higher than in aorta. These data suggest that TRPC3 and TRPC6 may play a role in mediating voltage-independent calcium entry in renal resistance vessels that is functionally distinct from that in aorta.

The Canonical Transient Receptor Potential 6 Channel as a Putative Phosphatidylinositol 3,4,5-Trisphosphate-Sensitive Calcium Entry System†

Biochemistry ◽  
2004 ◽  
Vol 43 (37) ◽  
pp. 11701-11708 ◽  
Author(s):  
Ping-Hui Tseng ◽  
Ho-Pi Lin ◽  
Hongzhen Hu ◽  
Chunbo Wang ◽  
Michael Xi Zhu ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Calcium Entry ◽  
Canonical Transient Receptor Potential ◽  
Transient Receptor

scholarly journals The Xenopus tropicalis orthologue of TRPV3 is heat sensitive

2015 ◽  
Vol 146 (5) ◽  
pp. 411-421 ◽  
Author(s):  
Beiying Liu ◽  
Feng Qin
Keyword(s):  
Mammalian Cells ◽  
Xenopus Oocytes ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Expression System ◽  
Receptor Potential ◽  
Functional Expression ◽  
Cold Sensitivity ◽  
Mammalian Cell Lines ◽  
Transient Receptor

Thermosensitive members of the transient receptor potential (TRP) family of ion channels (thermal TRP channels) play a crucial role in mammalian temperature sensing. Orthologues of these channels are present in lower vertebrates and, remarkably, some thermal TRP orthologues from different species appear to mediate opposing responses to temperature. For example, whereas the mammalian TRPV3 channel is activated by heat, frog TRPV3 is reportedly activated by cold. Intrigued by the potential implications of these opposing responses to temperature for the mechanism of temperature-dependent gating, we cloned Xenopus laevis TRPV3 and functionally expressed it in both mammalian cell lines and Xenopus oocytes. We found that, when expressed in mammalian cells, the recombinant channel lacks the reported cold sensitivity; rather, it is activated by temperatures >50°C. Furthermore, when expressed in mammalian cells, the frog orthologue shows other features characteristic of mammalian TRPV3, including activation by the agonist 2-aminoethoxydiphenyl borate and an increased response with repeated stimulation. We detected both heat- and cold-activated currents in Xenopus oocytes expressing the recombinant frog TRPV3 channel. However, cold-activated currents were also apparent in control oocytes lacking recombinant TRPV3. Our data indicate that frog TRPV3 resembles its mammalian orthologues in terms of its thermosensitivity and is intrinsically activated by heat. Thus, all known vanilloid receptors are activated by heat. Our data also show that Xenopus oocytes contain endogenous receptors that are activated by cold, and suggest that cold sensitivity of TRP channels established using Xenopus oocytes as a functional expression system may need to be revisited.

Cloning, expression and subcellular localization of two novel splice variants of mouse transient receptor potential channel 2

2000 ◽  
Vol 351 (1) ◽  
pp. 115-122 ◽  
Author(s):  
Thomas HOFMANN ◽  
Michael SCHAEFER ◽  
Günter SCHULTZ ◽  
Thomas GUDERMANN
Keyword(s):  
Membrane Trafficking ◽  
Fusion Proteins ◽  
Transient Receptor Potential ◽  
Splice Variants ◽  
Receptor Potential ◽  
Calcium Entry ◽  
Transient Receptor Potential Channels ◽  
Protein Fusion ◽  
Hek 293 ◽  
Transient Receptor

Transient receptor potential channels (TRPCs) are known as candidate molecular correlates of receptor-activated or store-operated calcium entry. While functional roles for most TRPCs have been suggested, the physiological relevance of TRPC2 remains obscure. Whereas human and bovine TRPC2 are candidate pseudogenes, full-length rodent TRPC2 transcripts have been reported. There is, however, considerable controversy concerning mRNA splicing, tissue distribution and the function of these proteins. We report the molecular cloning of two novel murine TRPC2 splice variants, mTRPC2α and mTRPC2β. mTRPC2α RNA is expressed at low levels in many tissues and cell systems, while mTRPC2β is exclusively and abundantly expressed in the vomeronasal organ (VNO). When expressed in human embryonic kidney (HEK)-293 cells, mTRPC2 did not enhance receptor- or store-activated calcium entry. In order to investigate the basis of such a functional defect, mTRPC2–green fluorescent protein fusion proteins were examined by confocal microscopy. Fusion proteins were retained in endomembranes when expressed in HEK-293 or other cells of epithelial or neuronal origin. Co-expression of TRPC2 with other TRPCs did not restore plasma-membrane trafficking. We conclude that TRPC2 may form functional channels in the cellular context of the VNO, but is unlikely to have a physiological function in other tissues. The sequences of mTRPC2α and mTRPC2β have been submitted to GenBank under the accession numbers AF230802 and AF230803 respectively.

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