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Association of plant K + in channels is mediated by conserved C‐termini and does not affect subunit assembly
Author(s) -
Ehrhardt Thomas,
Zimmermann Sabine,
Müller-Röber Bernd
Publication year - 1997
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(97)00502-4
Subject(s) - protein subunit , guard cell , potassium channel , ion channel , patch clamp , biophysics , c terminus , chemistry , mutant , biology , biochemistry , gene , amino acid , receptor
Inward rectifying potassium (K + in ) channels play an important role in turgor regulation and ion uptake in higher plants. Here, we report a previously unrecognized feature of these proteins: K + in channel C‐terminal polypeptides mediate channel protein interactions. Using a C‐terminal fragment of potato guard cell K + in channel KST1 in a yeast two‐hybrid screen two novel putative K + in channel proteins (SKT2 and SKT3) were identified by interaction of their C‐termini which contained a conserved domain (K HA ). Interactions were confirmed by Western blot‐related assays utilizing K + in channel C‐termini fused to green fluorescence protein. Although deletion of the K HA ‐domain abolished these interactions, K + in currents were still detectable by patch‐clamp measurements of insect cells expressing these KST1 mutants, indicating that formation of a functional channel does not depend on this C‐terminal domain.