SPRINT Home UMBER Home Contents Standard Search Advanced Search Relation Search

==SPRINT==> PRINTS View



  selected as


PR01606

Identifier
KCNE3CHANNEL  [View Relations]  [View Alignment]  
Accession
PR01606
No. of Motifs
3
Creation Date
12-SEP-2001
Title
KCNE voltage-gated K+ channel beta-3 subunit signature
Database References
PRINTS; PR00168 KCNECHANNEL
Literature References
1. MILLER, C.
An overview of the potassium channel family.
GENOME BIOL. 1(4) 1-5 (2000).
 
2. CONLEY, E.C. AND BRAMMAR, W.J.
MinK.
IN THE ION CHANNEL FACTSBOOK, VOLUME IV, ACADEMIC PRESS, 1999, PP.703-767.
 
3. ABBOT, G.W., BUTLER, M.H., BENDAHHOU, S., DALAKAS, M.C., PTACEK, L.J. AND
GOLDSTEIN, S.A.N.
MiRP2 forms potassium channels in skeletal muscle with Kv3.4 and is
associated with periodic paralysis.
CELL 104 217-231 (2001).
 
4. SCHROEDER, B.C., WALDEGGER, S., FEHR, S., BLEICH, M., WARTH, R., 
GREGER, R. AND JENTSCH, T.J.
A constitutively open potassium channel formed by KCNQ1 and KCNE3.
NATURE 403 196-199 (2000).

Documentation
Potassium ion (K+) channels are a structurally diverse group of proteins
that facilitate the flow of K+ ions across cell membranes. They are
ubiquitous, being present in virtually all cell types. Activation of K+
channels tends to hyperpolarise cells, reducing the membrane's electrical
resistance, dampening nervous activity. In eukaryotic cells, K+ channels
are involved in neural signalling and generation of the cardiac rhythm, and
act as effectors in signal transduction pathways involving G protein-
coupled receptors (GPCRs). In prokaryotic cells, they play a role in the
maintenance of ionic homeostasis [1].
 
Some types of K+ channel are closed at the resting potential of the cell,
but open on membrane depolarisation, and are thus known as voltage-gated 
channels. Each of these types of channel typically comprises 4 pore-forming
alpha subunits that may associate with one of a number of different types of
beta subunit. Two types of beta subunit (KCNE and KCNAB) are presently known
to associate with voltage-gated alpha subunits (Kv, KCNQ and eag-like).
However, not all combinations of alpha and beta subunits are possible.
 
The KCNE family of K+ channel subunits are membrane glycoproteins that 
possess a single transmembrane (TM) domain. They share no structural 
relationship with the alpha subunit proteins, which possess pore forming 
domains. The subunits appear to have a regulatory function, modulating the 
kinetics and voltage dependence of the alpha subunits of voltage-dependent
K+ channels [2]. KCNE subunits are formed from short polypeptides of ~130 
amino acids, and are divided into five subfamilies: KCNE1 (MinK/IsK),
KCNE2 (MiRP1), KCNE3 (MiRP2), KCNE4 (MiRP3) and KCNE1L (AMMECR2).
 
KCNE3 is known to associate with the pore forming subunits KCNQ1, KCNQ4,
HERG and Kv3.4. KCNE3 forms complexes with Kv3.4 in skeletal muscle -
KCNE3 mutations have been identified in families with skeletal muscle
disorders [3]. In the intestine, KCNE3 associates with KCNQ1 to form
channels that are stimulated by cAMP and are thought to be involved in
secretory diarrhoea and cystic fibrosis [4].
 
KCNE3CHANNEL is a 3-element fingerprint that provides a signature for the
KCNE voltage-gated K+ channel beta-3 subunit. The fingerprint was derived
from an initial alignment of 3 sequences: the motifs were drawn from
conserved regions spanning the N-terminal portion of the alignment, focusing
on those sections that characterise the KCNE3 subunits but distinguish them 
from the rest of the KCNE family - motifs 1-3 lie in the extracellular 
N-terminus. A single iteration on SPTR39.22_17.3f was required to reach 
convergence, no further sequences being identified beyond the starting set.
Summary Information
3 codes involving  3 elements
0 codes involving 2 elements
Composite Feature Index
3333
2000
123
True Positives
MIR2_HUMAN    MIR2_MOUSE    MIR2_RAT      
Sequence Titles
MIR2_HUMAN  MINIMUM POTASSIUM ION CHANNEL-RELATED PEPTIDE 2 (MIRP2) (MINK-RELATED PEPTIDE 2) - Homo sapiens (Human). 
MIR2_MOUSE MINIMUM POTASSIUM ION CHANNEL-RELATED PEPTIDE 2 (MIRP2) (MINK-RELATED PEPTIDE 2) - Mus musculus (Mouse).
MIR2_RAT MINIMUM POTASSIUM ION CHANNEL-RELATED PEPTIDE 2 (MIRP2) (MINK-RELATED PEPTIDE 2) - Rattus norvegicus (Rat).
Scan History
SPTR39.22_17.3f 1  100  NSINGLE    
Initial Motifs
Motif 1  width=18
Element Seqn Id St Int Rpt
METSNGTETWYMSLHAVL MIR2_MOUSE 1 1 -
METSNGTETWYKSLHAVL MIR2_RAT 1 1 -
METTNGTETWYESLHAVL MIR2_HUMAN 1 1 -

Motif 2 width=20
Element Seqn Id St Int Rpt
KALNTTLHSHLLCRPGPGPG MIR2_MOUSE 19 0 -
KALNTTLHSHLLCRPGPGPG MIR2_RAT 19 0 -
KALNATLHSNLLCRPGPGLG MIR2_HUMAN 19 0 -

Motif 3 width=18
Element Seqn Id St Int Rpt
PDNQTEDRRASLPGRNDN MIR2_MOUSE 39 0 -
PDNQTEDHRASLPGRNDN MIR2_RAT 43 4 -
PDNQTEERRASLPGRDDN MIR2_HUMAN 39 0 -
Final Motifs
Motif 1  width=18
Element Seqn Id St Int Rpt
METSNGTETWYMSLHAVL MIR2_MOUSE 1 1 -
METSNGTETWYKSLHAVL MIR2_RAT 1 1 -
METTNGTETWYESLHAVL MIR2_HUMAN 1 1 -

Motif 2 width=20
Element Seqn Id St Int Rpt
KALNTTLHSHLLCRPGPGPG MIR2_MOUSE 19 0 -
KALNTTLHSHLLCRPGPGPG MIR2_RAT 19 0 -
KALNATLHSNLLCRPGPGLG MIR2_HUMAN 19 0 -

Motif 3 width=18
Element Seqn Id St Int Rpt
PDNQTEDRRASLPGRNDN MIR2_MOUSE 39 0 -
PDNQTEDHRASLPGRNDN MIR2_RAT 43 4 -
PDNQTEERRASLPGRDDN MIR2_HUMAN 39 0 -