Cell Calcium. 2008 Mar;43(3):260-9. Epub 2007 Jul 12.

The first ankyrin-like repeat is the minimum indispensable key structure for functional assembly of homo- and heteromeric TRPC4/TRPC5 channels.External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c

Schindl, R., Frischauf, I., Kahr, H., Fritsch, R., Krenn, M., Derndl, A., Vales, E., Muik, M., Derler, I., Groschner, K., Romanin, C.,
["Institute for Biophysics, University of Linz, A-4040 Linz, Austria."]
The closely related TRPC4 and TRPC5 proteins, members of the canonical transient receptor potential (TRPC) family, assemble into either homo- or heterotetrameric, non-selective cation-channels. To elucidate domains that mediate channel complex formation, we evaluated dominant negative effects of N- or C-terminal TRPC4/5 fragments on respective currents of full-length proteins overexpressed in HEK293 cells with whole-cell electrophysiology. Confocal Forster Resonance Energy Transfer (FRET) measurements enabled to probe the interaction potential of these CFP/YFP-labelled fragments in vivo. Only N-terminal fragments that included the first ankyrin-like repeat potently down-regulated TRPC4/TRPC5 currents, while fragments including either the second ankyrin-like repeat and the coiled-coil domain or the C-terminus remained ineffective. Total internal reflection fluorescence (TIRF) microscopy data suggested that the dominant negative N-terminal fragments led to a predominantly intracellular localisation of coexpressed TRPC5 proteins. FRET measurements clearly revealed that only fragments including the first ankyrin-like repeat were able to multimerise. Moreover a TRPC5 mutant that lacked the first ankyrin-like repeat was unable to homo-multimerise, failed to interact with wild-type TRPC5 and resulted in non-functional channels.
PMID: 17624425External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c
Validation: In vivo validation Toggle 893349bafcc528f8346c51dc3420151d67b0126b2c122dd1017121c03fa0f69b
  Assay with endogenous proteins Assay with overexpressed proteins Reference
Cell or tissue Cell or tissue TRP channel construct Interactor construct
TRP channel Interactor Method Species Region Species Region
TRPC4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPC5 Fluorescence resonance energy transfer HEK293 Mouse Full-length Mouse Full-length 17624425
TRPC5 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPC4 Fluorescence resonance energy transfer HEK293 Mouse Full-length Mouse Full-length 17624425
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
Characterization Toggle 893349bafcc528f8346c51dc3420151d67b0126b2c122dd1017121c03fa0f69b
  Binding region mapping Stoichiometry Affinity (Kd) Reference
TRP channel Interactor
TRP channel Interactor Method Species Region Species Region
TRPC4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPC5 Fluorescence resonance energy transfer Mouse 1-292 Mouse 1-308 17624425
TRPC5 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPC4 Fluorescence resonance energy transfer Mouse 1-308 Mouse 1-292 17624425
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
TRP / Interactor

To prevent spam comments, we use reCAPTCHA. Please type correct words into the following box.