| 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. SANSOM, M.S.
Putting the parts together.
CURR.BIOL. 9(19) R738-R741 (1999).
4. LITTLETON, J.T. AND GANETZKY, B.
Ion Channels and synaptic organisation: analysis of the Drosophila genome.
NEURON 26 35-43 (2000).
5. CONLEY, E.C. AND BRAMMAR, W.J.
Shaker.
IN THE ION CHANNEL FACTSBOOK, VOLUME IV, ACADEMIC PRESS, 1999, PP.559-614.
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| 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, Kv channels belong to the subfamily of K+ channels whose
subunits contain 6 transmembrane (TM) domains: these are the voltage-
gated K+ (Kv) channels, the KCNQ channels, the EAG-like K+ channels and
3 kinds of Ca2+-activated K+ channels (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 [1-2].
The Kv family can be divided into 4 subfamilies on the basis of sequence
similarity and function: Shaker (Kv1), Shab (Kv2), Shaw (Kv3) and Shal
(Kv4). All consist of pore-forming alpha subunits that associate with
different types of beta subunit. To form a functional K+ channel pore,
4 alpha subunits and 4 beta subunits are required. The alpha subunits
have 6 well-conserved TM domains, a pore loop region and variable length
N- and C-termini. TM domains 5/6 and the loop region form the K+
channel pore through which the K+ ions pass [3].
The first Shaker (Kv1) sequence was found in Drosophila. Several vertebrate
K+ channels with similar amino acid sequences were subsequently found and,
together with the Drosophila Shaker channel, now constitute the Shaker (Kv1)
family. These channels are mostly expressed in the brain, but can also be
found in non-excitable cells, such as lymphocytes [4,5].
SHAKERCHANEL is a 5-element fingerprint that provides a signature for the
Skaker voltage-gated K+ channel family. The fingerprint was derived from an
initial alignment of 14 sequences: the motifs were drawn from conserved
regions spanning the N-terminal half of the alignment: motifs 1-3 reside in
the N-terminal domain; motif 4 spans the N-terminus of TM domain 1; and
motif 5 spans the C-terminus of TM domain 1. Three iterations on SPTR39_15f
were required to reach convergence, at which point a true set comprising 41
sequences was identified. Several partial matches were also found, all of
which are members of the Shaker family or are closely related potassium
channels that fail to make significant matches with 2 or more motifs.
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| Sequence Titles | CIK1_DROME VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN, ADULT (SHAKER-ALPHA) - Drosophila melanogaster (Fruit fly).
CIK1_HUMAN VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.1 (HUKI) (HBK1) - Homo sapiens (Human).
CIK1_MOUSE VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.1 (MK1) (MBK1) - Mus musculus (Mouse).
CIK1_RAT VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.1 (IA) (RBK1) (RCK1) - Rattus norvegicus (Rat).
CIK2_DROME VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN, LATE POPULATION (SHAKER- BETA) - Drosophila melanogaster (Fruit fly).
CIK2_HUMAN VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.2 (RBK2) (HBK5) (NGK1) (MK2) (HUKIV) - Homo sapiens (Human).
CIK2_MOUSE VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.2 (RBK2) (RCK5) (NGK1) (MK2) (HUKIV) - Mus musculus (Mouse), and Rattus norvegicus (Rat).
CIK2_XENLA VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.2 (XSHA2) - Xenopus laevis (African clawed frog).
CIK3_HUMAN VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.3 (HPCN3) (HGK5) (HUKIII) (HLK3) - Homo sapiens (Human).
CIK3_MOUSE VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.3 (MK3) - Mus musculus (Mouse).
CIK3_RAT VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.3 (RGK5) (RCK3) (KV3) - Rattus norvegicus (Rat).
CIK4_BOVIN VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.4 (BAK4) - Bos taurus (Bovine).
CIK4_DROME VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN, LARVAL (SHAKER-EPSILON) - Drosophila melanogaster (Fruit fly).
CIK4_HUMAN VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.4 (HK1) (HPCN2) (HBK4) (HUKII) - Homo sapiens (Human).
CIK4_MOUSE VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.4 - Mus musculus (Mouse).
CIK4_MUSPF VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.4 (FK1) - Mustela putorius furo (Ferret).
CIK4_RAT VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.4 (RCK4) (RHK1) (RK4) - Rattus norvegicus (Rat).
CIK5_HUMAN VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.5 (HK2) (HPCN1) - Homo sapiens (Human).
CIK5_MOUSE VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.5 (KV1-5) - Mus musculus (Mouse).
CIK5_MUSPF VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.5 - Mustela putorius furo (Ferret).
CIK5_RABIT VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.5 - Oryctolagus cuniculus (Rabbit).
CIK5_RAT VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.5 (KV1) (RCK7) - Rattus norvegicus (Rat).
CIK6_HUMAN VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.6 (HBK2) - Homo sapiens (Human).
CIK6_RAT VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV1.6 (RCK2) (KV2) - Rattus norvegicus (Rat).
O61335 POTASSIUM CHANNEL - Panulirus interruptus (California spiny lobster).
Q16322 CYCLIC GMP GATED POTASSIUM CHANNEL - Homo sapiens (Human).
Q16968 POTASSIUM CHANNEL - Aplysia californica (California sea hare).
Q25376 VOLTAGE-DEPENDENT POTASSIUM CHANNEL SQKV1A - Loligo opalescens (California market squid).
Q26597 POTASSIUM CHANNEL PROTEIN - Schistosoma mansoni (Blood fluke).
Q28293 DELAYED RECTIFIER K+ CHANNEL - Canis familiaris (Dog).
Q28656 GLIBENCLAMIDE-SENSITIVE VOLTAGE-GATED POTASSIUM CHANNEL - Oryctolagus cuniculus (Rabbit).
Q61923 MURINE POTASSIUM CHANNEL PROTEIN - Mus musculus (Mouse).
Q91781 POTASSIUM CHANNEL - Xenopus laevis (African clawed frog).
Q9I829 SHAKER-RELATED POTASSIUM CHANNEL TSHA2 - Oncorhynchus mykiss (Rainbow trout) (Salmo gairdneri).
Q9I830 SHAKER-RELATED POTASSIUM CHANNEL TSHA1 - Oncorhynchus mykiss (Rainbow trout) (Salmo gairdneri).
Q9MYX3 POTASSIUM CHANNEL SUBUNIT KV 1.2 - Oryctolagus cuniculus (Rabbit).
Q9PWM8 POTASSIUM CHANNEL SHAKER ALPHA SUBUNIT VARIANT CKV1.4(M) - Gallus gallus (Chicken).
Q9TS07 BAK5=DELAYED RECTIFIER POTASSIUM CHANNEL KV1.5 HOMOLOG - Bos taurus (Bovine).
Q9XXX0 TUKVI - Halocynthia roretzi (Sea squirt).
Q9YGX8 POTASSIUM CHANNEL SHAKER CKV1.4 - Gallus gallus (Chicken).
Q9Z1R6 VENTRICULAR POTASSIUM CHANNEL KV1.5 - Mus musculus (Mouse).
O70259 VOLTAGE-GATED POTASSIUM CHANNEL KV1.7 - Mus musculus (Mouse).
Q26095 POTASSIUM CHANNEL HOMOLOG - Polyorchis penicillatus (Hydromedusa).
Q28649 CGMP-GATED POTASSIUM CHANNEL - Oryctolagus cuniculus (Rabbit).
CIKE_RAT VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV3.2 (KSHIIIA) - Rattus norvegicus (Rat).
CIKG_HUMAN VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV3.4 (KSHIIIC) - Homo sapiens (Human).
CIKG_RAT VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN KV3.4 (RAW3) - Rattus norvegicus (Rat).
O18476 KV2 VOLTAGE-GATED POTASSIUM CHANNEL - Loligo pealeii (Longfin squid).
O76457 SHAW POTASSIUM CHANNEL KV3.1A - Aplysia californica (California sea hare).
Q09658 PUTATIVE POTASSIUM CHANNEL PROTEIN ZK1321.2 IN CHROMOSOME II - Caenorhabditis elegans.
Q9VWZ9 SH GENE PRODUCT - Drosophila melanogaster (Fruit fly).
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