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PR01464

Identifier
EAGCHANNEL  [View Relations]  [View Alignment]  
Accession
PR01464
No. of Motifs
12
Creation Date
01-DEC-2000
Title
EAG potassium channel signature
Database References
PRINTS; PR00169 KCHANNEL; PR01463 EAGCHANLFMLY
Literature References
1. MILLER, C.
An overview of the potassium channel family.
GENOME BIOL. 1(4) 1-5 (2000).
 
2. ASHCROFT, F.M.
Voltage-gated K+ channels.
IN ION CHANNELS AND DISEASE, ACADEMIC PRESS, 2000, PP.97-123.
 
3. LITTLETON, J.T. AND GANETZKY, B.
Ion Channels and Synaptic Organisation: analysis of the Drosophila Genome	
NEURON 26 35-43 (2000).
 
4. FRINGS, S., BRULL, N., DZEJA, C. ANGELE, A., HAGEN, V. AND KAUPP U.B.
Characterisation of a ether-a-go-go channels present in photoreceptors
reveals similarity to IK a K+ current in rod inner segments.
J.GEN.PHYSIOL. 111 583-599 (1998).

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].
 
Structurally, EAG channels belong to the subfamily of K+ channels whose
subunits contain 6 transmembrane (TM) domains: these are the voltage-gated
K+ channels, the KCNQ channels, the EAG-like K+ channels and 3 kinds of
Ca2+-activated K+ channel (BK, IK and SK) [2]. All K+ channels share a
characteristic sequence feature: a TMxTVGYG motif that resides between the
2 C-terminal membrane-spanning helices, and forms the K+-selective pore 
domain [1]. However, unlike other families within this structural class,
EAG channels possess a cyclic nucleotide binding domain within their 
putative intracellular C-termini.
 
The first EAG K+ channel was identified in Drosophila, following a screen 
for mutations giving rise to behavioural abnormalities. Disruption of the
Eag gene caused an ether-induced, leg-shaking behaviour. Subsequent studies
have revealed a conserved multi-gene family of EAG-like K+ channels, which
are present in Homo sapiens and many other species. Based on the varying
functional properties of the channels, the family has been divided into
3 subfamilies: EAG, ELK and ERG. Interestingly, C.elegans appears to lack
the ELK type [3].
 
The EAG subfamily has been expressed in heterologous systems to reveal their
biophysical and pharmacological functions and to determine their currents in
native tissues. All mammalian EAG subfamily K+ channels that have been 
identified have properties typical of delayed rectifiers, with no measurable
inactivation [5]. Only the Drosophila Eag channel exhibits partial
inactivation.
 
EAGCHANNEL is a 12-element fingerprint that provides a signature for the
EAG potassium channels. The fingerprint was derived from an initial
alignment of 7 sequences: the motifs were drawn from conserved regions
spanning virtually the full alignment length, focusing on those sections
that characterise the EAG channels but distinguish them from other members
of the K+ channel superfamily - motifs 1-4 reside within the N-terminal 
domain; motif 5 encodes putative TM domain 1; motif 6 encompasses TM domain 
3; motif 7 spans part of the loop between TM domains 3 and 4; motif 8 spans
the loop between TM domains 5 and 6; and motifs 9-12 reside within the 
C-terminal region. Four iterations on SPTR39_14f were required to reach 
convergence, at which point a true set comprising 9 sequences was 
identified. A single partial match was found, Q9XYX7, the C.elegans EAG K+
channel EGL-2, which fails to make significant matches with motifs 1,2 4,
8 and 12.
Summary Information
   9 codes involving 12 elements
0 codes involving 11 elements
0 codes involving 10 elements
0 codes involving 9 elements
0 codes involving 8 elements
1 codes involving 7 elements
0 codes involving 6 elements
0 codes involving 5 elements
0 codes involving 4 elements
0 codes involving 3 elements
0 codes involving 2 elements
Composite Feature Index
12999999999999
11000000000000
10000000000000
9000000000000
8000000000000
7001011101110
6000000000000
5000000000000
4000000000000
3000000000000
2000000000000
123456789101112
True Positives
CIKE_DROME    O18965        O18966        O76035        
O95259 Q60603 Q63472 Q9QXT2
Q9VXZ6
True Positive Partials
Codes involving 7 elements
Q9XYX7
Sequence Titles
CIKE_DROME  POTASSIUM CHANNEL PROTEIN EAG - Drosophila melanogaster (Fruit fly). 
O18965 EAG CHANNEL - Bos taurus (Bovine).
O18966 EAG CHANNEL - Bos taurus (Bovine).
O76035 POTASSIUM CHANNEL H-EAG - Homo sapiens (Human).
O95259 VOLTAGE-GATED POTASSIUM CHANNEL EAGB - Homo sapiens (Human).
Q60603 LONG (ELECTOCARDIOGRAPHIC) QT SYNDROME 2 (POTASSIUM CHANNEL SUBUNIT) - Mus musculus (Mouse).
Q63472 POTASSIUM CHANNEL SUBUNIT - Rattus norvegicus (Rat).
Q9QXT2 POTASIUM CHANNEL EAG2 - Rattus norvegicus (Rat).
Q9VXZ6 EAG PROTEIN - Drosophila melanogaster (Fruit fly).

Q9XYX7 EAG K+ CHANNEL EGL-2 - Caenorhabditis elegans.
Scan History
SPTR39_14f 4  10   NSINGLE    
Initial Motifs
Motif 1  width=8
Element Seqn Id St Int Rpt
ENIVRRSN O18965 19 19 -
ENIVRRSN Q63472 19 19 -
ENIVRRSN Q60603 19 19 -
ENIVRRSN O95259 19 19 -
ENIVRRSN O76035 19 19 -
ENIVRRSN O18966 19 19 -
ENIIRRSN CIKE_DROME 17 17 -

Motif 2 width=14
Element Seqn Id St Int Rpt
APIRNEQDKVVLFL O18965 114 87 -
APIRNEQDKVVLFL Q63472 114 87 -
APIRNEQDKVVLFL Q60603 114 87 -
APIRNEQDKVVLFL O95259 114 87 -
APIRNEQDKVVLFL O76035 114 87 -
APIRNEQDKVVLFL O18966 114 87 -
APIRNERDLVVLFL CIKE_DROME 134 109 -

Motif 3 width=12
Element Seqn Id St Int Rpt
TFSDITAFKQPI O18965 129 1 -
TFSDITAFKQPI Q63472 129 1 -
TFSDITAFKQPI Q60603 129 1 -
TFSDITAFKQPI O95259 129 1 -
TFSDITAFKQPI O76035 129 1 -
TFSDITAFKQPI O18966 129 1 -
TFRDITALKQPI CIKE_DROME 149 1 -

Motif 4 width=13
Element Seqn Id St Int Rpt
KFARLTRALTSSR O18965 150 9 -
KFARLTRALTSSR Q63472 150 9 -
KFARLTRALTSSR Q60603 150 9 -
KFARLTRALTSSR O95259 150 9 -
KFARLTRALTSSR O76035 150 9 -
KFARLTRALTSSR O18966 150 9 -
KFAKLARSVTRSR CIKE_DROME 173 12 -

Motif 5 width=18
Element Seqn Id St Int Rpt
QLGSDILPQYKQEAPKTP O18965 189 26 -
QLGSDILPQYKQEAPKTP Q63472 189 26 -
QLGSDILPQYKQEAPKTP Q60603 189 26 -
QLGSDILPQYKQEAPKTP O95259 189 26 -
QLGSDILPQYKQEAPKTP O76035 189 26 -
QLGSDILPQYKQEAPKTP O18966 189 26 -
SLSADIMPQYRQEAPKTP CIKE_DROME 208 22 -

Motif 6 width=9
Element Seqn Id St Int Rpt
VIDLLSCLP O18965 297 90 -
VIDLLSCLP Q63472 297 90 -
VIDLLSCLP Q60603 297 90 -
VIDLLSCLP O95259 297 90 -
VIDLLSCLP O76035 297 90 -
VIDLLSCLP O18966 297 90 -
IIDLLSCLP CIKE_DROME 317 91 -

Motif 7 width=10
Element Seqn Id St Int Rpt
GISSLFSSLK O18965 318 12 -
GISSLFSSLK Q63472 318 12 -
GISSLFSSLK Q60603 345 39 -
GISSLFSSLK O95259 345 39 -
GISSLFSSLK O76035 318 12 -
GISSLFSSLK O18966 345 39 -
GIGSLFSALK CIKE_DROME 338 12 -

Motif 8 width=7
Element Seqn Id St Int Rpt
SWLYQLA O18965 390 62 -
SWLYQLA Q63472 390 62 -
SWLYQLA Q60603 417 62 -
SWLYQLA O95259 417 62 -
SWLYQLA O76035 390 62 -
SWLYQLA O18966 417 62 -
SWLWKLA CIKE_DROME 405 57 -

Motif 9 width=13
Element Seqn Id St Int Rpt
TEKVLQICPKDMR O18965 525 128 -
TEKVLQICPKDMR Q63472 525 128 -
TEKVLQICPKDMR Q60603 552 128 -
TEKVLQICPKDMR O95259 552 128 -
TEKVLQICPKDMR O76035 525 128 -
TEKVLQICPKDMR O18966 552 128 -
TEKVLNCCPKDMK CIKE_DROME 542 130 -

Motif 10 width=16
Element Seqn Id St Int Rpt
EFYTAFSHSFSRNLIL O18965 655 117 -
EFYTAFSHSFSRNLIL Q63472 655 117 -
EFYTAFSHSFSRNLIL Q60603 682 117 -
EFYTAFSHSFSRNLIL O95259 682 117 -
EFYTAFSHSFSRNLIL O76035 655 117 -
EFYTAFSHSFSRNLIL O18966 682 117 -
DFYSAFANSFARNLVL CIKE_DROME 672 117 -

Motif 11 width=15
Element Seqn Id St Int Rpt
RKRIVFRKISDVKRE O18965 675 4 -
RKRIVFRKISDVKRE Q63472 675 4 -
RKRIVFRKISDVKRE Q60603 702 4 -
RKRIVFRKISDVKRE O95259 702 4 -
RKRIVFRKISDVKRE O76035 675 4 -
RKRIVFRKISDVKRE O18966 702 4 -
RHRLIFRRVADVKRE CIKE_DROME 692 4 -

Motif 12 width=12
Element Seqn Id St Int Rpt
DHPVRRLFQRFR O18965 707 17 -
DHPVRRLFQRFR Q63472 707 17 -
DHPVRRLFQRFR Q60603 734 17 -
DHPVRRLFQRFR O95259 734 17 -
DHPVRRLFQRFR O76035 707 17 -
DHPVRRLFQRFR O18966 734 17 -
DHLVRKIFSKFR CIKE_DROME 724 17 -
Final Motifs
Motif 1  width=8
Element Seqn Id St Int Rpt
ENIVRRSN O18965 19 19 -
ENIVRRSN Q63472 19 19 -
ENIVRRSN Q60603 19 19 -
ENIVRRSN O95259 19 19 -
ENIVRRSN O76035 19 19 -
ENIVRRSN O18966 19 19 -
ENIVRRSS Q9QXT2 17 17 -
ENIIRRSN Q9VXZ6 17 17 -
ENIIRRSN CIKE_DROME 17 17 -

Motif 2 width=14
Element Seqn Id St Int Rpt
APIRNEQDKVVLFL O18965 114 87 -
APIRNEQDKVVLFL Q63472 114 87 -
APIRNEQDKVVLFL Q60603 114 87 -
APIRNEQDKVVLFL O95259 114 87 -
APIRNEQDKVVLFL O76035 114 87 -
APIRNEQDKVVLFL O18966 114 87 -
APIRNEHEKVVLFL Q9QXT2 112 87 -
APIRNERDLVVLFL Q9VXZ6 134 109 -
APIRNERDLVVLFL CIKE_DROME 134 109 -

Motif 3 width=12
Element Seqn Id St Int Rpt
TFSDITAFKQPI O18965 129 1 -
TFSDITAFKQPI Q63472 129 1 -
TFSDITAFKQPI Q60603 129 1 -
TFSDITAFKQPI O95259 129 1 -
TFSDITAFKQPI O76035 129 1 -
TFSDITAFKQPI O18966 129 1 -
TFKDITLFKQPI Q9QXT2 127 1 -
TFRDITALKQPI Q9VXZ6 149 1 -
TFRDITALKQPI CIKE_DROME 149 1 -

Motif 4 width=13
Element Seqn Id St Int Rpt
KFARLTRALTSSR O18965 150 9 -
KFARLTRALTSSR Q63472 150 9 -
KFARLTRALTSSR Q60603 150 9 -
KFARLTRALTSSR O95259 150 9 -
KFARLTRALTSSR O76035 150 9 -
KFARLTRALTSSR O18966 150 9 -
KFARLTRALTNSR Q9QXT2 148 9 -
KFAKLARSVTRSR Q9VXZ6 173 12 -
KFAKLARSVTRSR CIKE_DROME 173 12 -

Motif 5 width=18
Element Seqn Id St Int Rpt
QLGSDILPQYKQEAPKTP O18965 189 26 -
QLGSDILPQYKQEAPKTP Q63472 189 26 -
QLGSDILPQYKQEAPKTP Q60603 189 26 -
QLGSDILPQYKQEAPKTP O95259 189 26 -
QLGSDILPQYKQEAPKTP O76035 189 26 -
QLGSDILPQYKQEAPKTP O18966 189 26 -
QLGSDILPQYKQEAPKTP Q9QXT2 186 25 -
SLSADIMPQYRQEAPKTP Q9VXZ6 208 22 -
SLSADIMPQYRQEAPKTP CIKE_DROME 208 22 -

Motif 6 width=9
Element Seqn Id St Int Rpt
VIDLLSCLP O18965 297 90 -
VIDLLSCLP Q63472 297 90 -
VIDLLSCLP Q60603 297 90 -
VIDLLSCLP O95259 297 90 -
VIDLLSCLP O76035 297 90 -
VIDLLSCLP O18966 297 90 -
VIDLLSCLP Q9QXT2 294 90 -
IIDLLSCLP Q9VXZ6 317 91 -
IIDLLSCLP CIKE_DROME 317 91 -

Motif 7 width=10
Element Seqn Id St Int Rpt
GISSLFSSLK O18965 318 12 -
GISSLFSSLK Q63472 318 12 -
GISSLFSSLK Q60603 345 39 -
GISSLFSSLK O95259 345 39 -
GISSLFSSLK O76035 318 12 -
GISSLFSSLK O18966 345 39 -
GISSLFSSLK Q9QXT2 315 12 -
GIGSLFSALK Q9VXZ6 338 12 -
GIGSLFSALK CIKE_DROME 338 12 -

Motif 8 width=7
Element Seqn Id St Int Rpt
SWLYQLA O18965 390 62 -
SWLYQLA Q63472 390 62 -
SWLYQLA Q60603 417 62 -
SWLYQLA O95259 417 62 -
SWLYQLA O76035 390 62 -
SWLYQLA O18966 417 62 -
SWLYQLA Q9QXT2 387 62 -
SWLWKLA Q9VXZ6 405 57 -
SWLWKLA CIKE_DROME 405 57 -

Motif 9 width=13
Element Seqn Id St Int Rpt
TEKVLQICPKDMR O18965 525 128 -
TEKVLQICPKDMR Q63472 525 128 -
TEKVLQICPKDMR Q60603 552 128 -
TEKVLQICPKDMR O95259 552 128 -
TEKVLQICPKDMR O76035 525 128 -
TEKVLQICPKDMR O18966 552 128 -
TEKVLSICPKDMR Q9QXT2 521 127 -
TEKVLNYCPKDMK Q9VXZ6 542 130 -
TEKVLNCCPKDMK CIKE_DROME 542 130 -

Motif 10 width=16
Element Seqn Id St Int Rpt
EFYTAFSHSFSRNLIL O18965 655 117 -
EFYTAFSHSFSRNLIL Q63472 655 117 -
EFYTAFSHSFSRNLIL Q60603 682 117 -
EFYTAFSHSFSRNLIL O95259 682 117 -
EFYTAFSHSFSRNLIL O76035 655 117 -
EFYTAFSHSFSRNLIL O18966 682 117 -
DFYTAFANSFSRNLTL Q9QXT2 651 117 -
DFYSAFANSFARNLVL Q9VXZ6 672 117 -
DFYSAFANSFARNLVL CIKE_DROME 672 117 -

Motif 11 width=15
Element Seqn Id St Int Rpt
RKRIVFRKISDVKRE O18965 675 4 -
RKRIVFRKISDVKRE Q63472 675 4 -
RKRIVFRKISDVKRE Q60603 702 4 -
RKRIVFRKISDVKRE O95259 702 4 -
RKRIVFRKISDVKRE O76035 675 4 -
RKRIVFRKISDVKRE O18966 702 4 -
RKRIIFRKISDVKKE Q9QXT2 671 4 -
RHRLIFRKVADVKRE Q9VXZ6 692 4 -
RHRLIFRRVADVKRE CIKE_DROME 692 4 -

Motif 12 width=12
Element Seqn Id St Int Rpt
DHPVRRLFQRFR O18965 707 17 -
DHPVRRLFQRFR Q63472 707 17 -
DHPVRRLFQRFR Q60603 734 17 -
DHPVRRLFQRFR O95259 734 17 -
DHPVRRLFQRFR O76035 707 17 -
DHPVRRLFQRFR O18966 734 17 -
DHPVRKLFQKFK Q9QXT2 703 17 -
DHLVRKIFSKFR Q9VXZ6 724 17 -
DHLVRKIFSKFR CIKE_DROME 724 17 -