Journal Article

PreJuSER-57067

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png A helical region in the C terminus of small-conductance Ca2+-activated K+ channels controls assembly with apo-calmodulin

Wissmann, R. ; Bildl, W. ; Neumann, H. ; Rivard, A. F. ; Klocker, N. ; Weitz, D.FZJ* ; Schulte, U. ; Adelman, J. P. ; Bentrop, D. ; Fakler, M. M.

2002
Soc. Bethesda, Md.

This record in other databases:      

Please use a persistent id in citations: http://hdl.handle.net/2128/2649  doi:10.1074/jbc.M109240200

Abstract: Small conductance Ca(2+)-activated potassium (SK) channels underlie the afterhyperpolarization that follows the action potential in many types of central neurons. SK channels are voltage-independent and gated solely by intracellular Ca(2+) in the submicromolar range. This high affinity for Ca(2+) results from Ca(2+)-independent association of the SK alpha-subunit with calmodulin (CaM), a property unique among the large family of potassium channels. Here we report the solution structure of the calmodulin binding domain (CaMBD, residues 396-487 in rat SK2) of SK channels using NMR spectroscopy. The CaMBD exhibits a helical region between residues 423-437, whereas the rest of the molecule lacks stable overall folding. Disruption of the helical domain abolishes constitutive association of CaMBD with Ca(2+)-free CaM, and results in SK channels that are no longer gated by Ca(2+). The results show that the Ca(2+)-independent CaM-CaMBD interaction, which is crucial for channel function, is at least in part determined by a region different in sequence and structure from other CaM-interacting proteins.

Keyword(s): Amino Acid Sequence (MeSH) ; Animals (MeSH) ; Calcium: metabolism (MeSH) ; Calmodulin: chemistry (MeSH) ; Calmodulin: metabolism (MeSH) ; Immunohistochemistry (MeSH) ; Models, Molecular (MeSH) ; Molecular Sequence Data (MeSH) ; Nuclear Magnetic Resonance, Biomolecular (MeSH) ; Potassium Channels: chemistry (MeSH) ; Potassium Channels: metabolism (MeSH) ; Potassium Channels, Calcium-Activated (MeSH) ; Protein Conformation (MeSH) ; Small-Conductance Calcium-Activated Potassium Channels (MeSH) ; Xenopus (MeSH) ; Calmodulin ; Potassium Channels ; Potassium Channels, Calcium-Activated ; Small-Conductance Calcium-Activated Potassium Channels ; Calcium ; J

Note: Record converted from VDB: 12.11.2012

---

Contributing Institute(s):

1. Zelluläre Signalverarbeitung (IBI-1)

Research Program(s):

1. Neurowissenschaften (L01)

Appears in the scientific report 2002

---

Database coverage:

---