Homo sapiens gene KCNMB2, encoding potassium large conductance calcium-activated channel, subfamily M, beta member 2.
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SUMMARY back to top
RefSeq summary
[KCNMB2] MaxiK channels are large conductance, voltage and calcium-sensitive potassium channels which are fundamental to the control of smooth muscle tone and neuronal excitability. MaxiK channels can be formed by 2 subunits: the pore-forming alpha subunit and the modulatory beta subunit. The protein encoded by this gene is an auxiliary beta subunit which decreases the activation time of MaxiK alpha subunit currents. Two variants encoding the same protein have been found for this gene. [provided by RefSeq].

RefSeq annotates 2 representative transcripts (NM included in AceView variants .a and .c), but Homo sapiens cDNA sequences in GenBank, dbEST, Trace and SRA, filtered against clone rearrangements, coaligned on the genome and clustered in a minimal non-redundant way by the manually supervised AceView program, support at least 8 spliced variants.

AceView synopsis, each blue text links to tables and details
Expression: According to AceView, this gene is well expressed, 0.7 times the average gene in this release. The sequence of this gene is defined by 82 GenBank accessions from 73 cDNA clones, some from brain (seen 15 times), pancreas (10), lung (9), carcinoid (7), kidney (6), purified pancreatic islet (4), islets of langerhans (3) and 19 other tissues. We annotate structural defects or features in 7 cDNA clones.
Alternative mRNA variants and regulation: The gene contains 12 distinct gt-ag introns. Transcription produces 9 different mRNAs, 8 alternatively spliced variants and 1 unspliced form. There are 3 probable alternative promotors, 3 non overlapping alternative last exons and 8 validated alternative polyadenylation sites (see the diagram). The mRNAs appear to differ by truncation of the 5' end, truncation of the 3' end, presence or absence of 6 cassette exons, overlapping exons with different boundaries.
Efficacy of translation may be reduced by the presence of a shorter translated product (uORF) initiating at an AUG upstream of the main open reading frame (in variant aAug10, bAug10).
Function: There are 15 articles specifically referring to this gene in PubMed. Functionally, the gene has been proposed to participate in pathway (Vascular smooth muscle contraction) and processes (detection of calcium ion, potassium ion transport, regulation of action potential, regulation of action potential in neuron, regulation of vasoconstriction). Proteins are expected to have molecular functions (calcium-activated potassium channel activity, ion channel inhibitor activity, potassium channel regulator activity) and to localize in various compartments (integral to plasma membrane, voltage-gated potassium channel complex).
Protein coding potential: 3 spliced mRNAs putatively encode the same good protein, some containing domains Calcium-activated potassium channel, beta subunit, KCNMB2, ball and chain domain [Pfam], some transmembrane domains [Psort2]. The remaining 6 mRNA variants (5 spliced, 1 unspliced; 2 partial) appear not to encode good proteins.

Please quote: AceView: a comprehensive cDNA-supported gene and transcripts annotation, Genome Biology 2006, 7(Suppl 1):S12.
Map on chromosome 3, links to other databases and other names
Map: This gene KCNMB2 maps on chromosome 3, at 3q26.32 according to Entrez Gene. In AceView, it covers 308.23 kb, from 178253993 to 178562217 (NCBI 37, August 2010), on the direct strand.
Links to: manual annotations from KEGG_04270, the SNP view, gene overviews from Entrez Gene 10242, GeneCards, expression data from ECgene, UniGene, molecular and other annotations from UCSC, or our GOLD analysis.
The previous AceView annotation is here.
Other names: The gene is also known as KCNMB2, MGC22431 or LOC10242, neegawbo. It has been described as calcium-activated potassium channel subunit beta-2, hbeta2, hbeta3, BKbeta2, slo-beta-2, k(VCA)beta-2, OTTHUMP00000211869, OTTHUMP00000211870, OTTHUMP00000211871, OTTHUMP00000211872, OTTHUMP00000211874, BK channel subunit beta-2, MaxiK channel beta 2 subunit, maxi K channel subunit beta-2, charybdotoxin receptor subunit beta-2, large-conductance Ca2+-activated K+ channel beta2 subunit, calcium-activated potassium channel, subfamily M subunit beta-2, large conductance calcium-activated potassium channel beta 2 subunit.
Closest AceView homologs in other species ?
The closest mouse gene, according to BlastP, is the AceView gene Kcnmb2 (e= 10-133).
The closest C.elegans gene, according to BlastP, is the AceView/WormGene math-4 (e=0.89), which may contain interesting functional annotation
RNA_seq discoveries back to top
Expression/conservation in primates tissues evaluated by cross-mapping to human. back to top
KCNMB2 Gene expression in 15 primates, 16 tissues, from the NHPRTR project in sFPKM BAB SkeletalMuscle WholeBlood CHP Kidney Liver Lung Spleen CMC CMM Cerebellum HUM Brain Colon Heart LymphNode Ovary Testis JMI BoneMarrow MLM OWL PTM RMC RMI Pituitary SQM Thymus MST SMY RTL 0.32 0.83 1.10 0.72 0.68 1.78 0.42 1.02 2.52 0.04 3.57 4.39 1.18 0.29 0.96 2.90 0.39 1.78 0.29 0.06 0.08 0.06 0.18 1.78 9.41 1.02 26.6 1.45 0.10 0.13 0.55 0.39 0.42 3.57 0.12 0.18 0.27 2.90 0.34 0.83 1.78 6.65 1.55 0.51 3.82 0.09 8.19 0.78 1.91 0.72 0.68 16.4 0.06 0.10 0.10 1.35 0.59 4.39 3.10 0.78 0.11 0.10 0.34 0.29 1.55 13.3 3.10 8.78 0.34 1.55 15.3 0.63 0.48 0.17 0.07 0.10 0.11 2.05 6.21 1.18 5.79 0.26 0.78 0.83 1.91 1.55 5.79 7.13 1.45 1.78 0.24 0.63 0.10 0.12 0.09 0.13 2.19 1.66 0.27 5.79 10.8 13.3 1.91 0.07 0.10 0.29 1.55 0.17 1.91 0.39 0.22 0.83 0.59 0.09 0.12 4.71 0.29 10.1 3.57 0.59 0.09 0.51 0.22 0.13 5.40 0.19 1.10 1.91 6.65 0.72 Expression quantiles None Weak 1 2 3 4 5 6 7 8 10 20 This gene All genes log2 distributions RNA-seq gene expression profile across 16 selected tissues from the Non-Human Primates Reference Transcriptome Resource (link to NHPRTR project).
- Primates: Apes (HUM: Human (Illumina BodyMap 2), CHP: Chimpanzee), Old World monkeys (PTM: Pig-Tailed Macaque, JMI Japanese Macaque, RMI Rhesus Macaque Indian, RMC Rhesus Macaque Chinese, CMM Cynomolgus Macaque Mauritian, CMC Cynomolgus Macaque Chinese, BAB Olive Baboon, SMY Sooty Mangabey); New World monkeys (MST common Marmoset, SQM Squirrel Monkey, OWL Owl Monkey); and Lemurs (MLM Mouse Lemur, RTL Ring-Tailed Lemur).
- The level for significantly expressed genes is color coded in 8 equal sized bins (light to dark green). Light gray is for weak not-accurately measured expression (2 to 8 reads above intergenic background); dark gray for no expression or no sequence conservation (0 read in gene). The plot to the right shows the distribution of measured expression values in all tissues for all genes (blue) and for this gene (green), in Magic index = log2(1000 sFPKM).
You may also examine the strand-specific genome coverage plots on the experimental AceView/Magic hub at UCSC, by tissue or by species. Tracks may be slow to load; please reload if some tracks come up yellow-greenish, and thanks to UCSC for the great work!.
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          Complete gene on genome diagram: back to top
Please choose between the zoomable GIF version., and the HTML5/SVG version.
This diagram shows in true scale the gene on the genome, the mRNAs and the cDNA clones.
Compact gene diagram back to top
Gene KCNMB2 5' 3' encoded on plus strand of chromosome 3 from 178,253,993 to 178,562,217 1288 2118 2773 2472 a [NM] 8 2118 2773 2472 b 7 415 2118 2773 2472 c [NM] d-u 398 415 2118 e 8 85 126 2773 f 1288 85 g 1 h 17 i 1 2kb 0 475 bp exon 475 bp exon 27 bp uORF 475 bp exon 270631 bp [gt-ag] intron 15 GenBank accessions 1273 RNA-seq supporting reads 68 UHR pooled cells 380 Brain 796 Neuroblastoma 29 Other (also 550 Primates bodymap) 123 bp exon 123 bp exon 123 bp exon 18122 bp [gt-ag] intron 41 GenBank accessions 2077 RNA-seq supporting reads 184 UHR pooled cells 557 Brain 1289 Neuroblastoma 47 Other (also 909 Primates bodymap) 171 bp exon 171 bp exon 2419 bp [gt-ag] intron 33 GenBank accessions 2740 RNA-seq supporting reads 292 UHR pooled cells 692 Brain 1691 Neuroblastoma 65 Other (also 923 Primates bodymap) 196 bp exon 196 bp exon 14279 bp [gt-ag] intron 18 GenBank accessions 2454 RNA-seq supporting reads 224 UHR pooled cells 703 Brain 1477 Neuroblastoma 50 Other (also 816 Primates bodymap) 1777 bp exon 1777 bp exon 45 accessions, NM_181361.1 some from brain (seen 8 times) kidney (5), lung (5) carcinoid (3), pancreatic islet (3) capped 5' end, 11 accessions Validated 3' end, 1 accession Validated 3' end, 2 accessions Validated 3' end, 2 accessions 1777 bp exon 285 bp exon 285 bp exon 285 bp uORF 248358 bp [gt-ag] intron 3 GenBank accessions 5 RNA-seq supporting reads 5 UHR pooled cells (also 10 Primates bodymap) 285 bp uORF 123 bp exon 123 bp exon 123 bp exon 18122 bp [gt-ag] intron 41 GenBank accessions 2077 RNA-seq supporting reads 184 UHR pooled cells 557 Brain 1289 Neuroblastoma 47 Other (also 909 Primates bodymap) 171 bp exon 171 bp exon 2419 bp [gt-ag] intron 33 GenBank accessions 2740 RNA-seq supporting reads 292 UHR pooled cells 692 Brain 1691 Neuroblastoma 65 Other (also 923 Primates bodymap) 196 bp exon 196 bp exon 14279 bp [gt-ag] intron 18 GenBank accessions 2454 RNA-seq supporting reads 224 UHR pooled cells 703 Brain 1477 Neuroblastoma 50 Other (also 816 Primates bodymap) 1776 bp exon 1776 bp exon 1 accession from ovary Validated 3' end, 1 accession 1776 bp exon 155 bp exon 155 bp exon 57 bp uORF 155 bp exon 236157 bp [gt-ag] intron 5 GenBank accessions 2 RNA-seq supporting reads 2 UHR pooled cells 77 bp exon 77 bp exon 12124 bp [gt-ag] intron 8 GenBank accessions 407 RNA-seq supporting reads 53 UHR pooled cells 82 Brain 261 Neuroblastoma 11 Other (also 18 Primates bodymap) 123 bp exon 123 bp exon 123 bp exon 18122 bp [gt-ag] intron 41 GenBank accessions 2077 RNA-seq supporting reads 184 UHR pooled cells 557 Brain 1289 Neuroblastoma 47 Other (also 909 Primates bodymap) 171 bp exon 171 bp exon 2419 bp [gt-ag] intron 33 GenBank accessions 2740 RNA-seq supporting reads 292 UHR pooled cells 692 Brain 1691 Neuroblastoma 65 Other (also 923 Primates bodymap) 196 bp exon 196 bp exon 14279 bp [gt-ag] intron 18 GenBank accessions 2454 RNA-seq supporting reads 224 UHR pooled cells 703 Brain 1477 Neuroblastoma 50 Other (also 816 Primates bodymap) 1777 bp exon 1777 bp exon 10 accessions, NM_005832.3 some from carcinoid (seen 4 times) lung (4), kidney (once) liver (once), neuroendocrine lung carcinoid (once) Validated 3' end, 1 accession Validated 3' end, 1 accession 1777 bp exon 914 bp exon 914 bp exon 4 accessions, some from pancreas (seen 3 times) purified pancreatic islet (3) breast normal (once) 914 bp exon 507 bp exon 258430 bp [gt-ag] intron 3 GenBank accessions 395 RNA-seq supporting reads 64 UHR pooled cells 85 Brain 235 Neuroblastoma 11 Other (also 28 Primates bodymap) 77 bp exon 12124 bp [gt-ag] intron 8 GenBank accessions 407 RNA-seq supporting reads 53 UHR pooled cells 82 Brain 261 Neuroblastoma 11 Other (also 18 Primates bodymap) 123 bp exon 123 bp exon 18122 bp [gt-ag] intron 41 GenBank accessions 2077 RNA-seq supporting reads 184 UHR pooled cells 557 Brain 1289 Neuroblastoma 47 Other (also 909 Primates bodymap) 66 bp exon 3 accessions, some from brain (seen 3 times) capped 5' end, 3 accessions 66 bp exon 100 bp exon 248358 bp [gt-ag] intron 3 GenBank accessions 5 RNA-seq supporting reads 5 UHR pooled cells (also 10 Primates bodymap) 123 bp exon 17092 bp [gt-ag] intron 3 GenBank accessions 82 RNA-seq supporting reads 4 UHR pooled cells 10 Brain 68 Neuroblastoma 125 bp exon 125 bp exon 905 bp [gt-ag] intron 2 GenBank accessions 124 RNA-seq supporting reads 6 UHR pooled cells 14 Brain 104 Neuroblastoma 171 bp exon 2419 bp [gt-ag] intron 33 GenBank accessions 2740 RNA-seq supporting reads 292 UHR pooled cells 692 Brain 1691 Neuroblastoma 65 Other (also 923 Primates bodymap) 89 bp exon 2 accessions, some from islets of langerhans (seen 2 times) pancreas (2) 89 bp exon 313 bp exon 270631 bp [gt-ag] intron 15 GenBank accessions 1273 RNA-seq supporting reads 68 UHR pooled cells 380 Brain 796 Neuroblastoma 29 Other (also 550 Primates bodymap) 123 bp exon 123 bp exon 17092 bp [gt-ag] intron 3 GenBank accessions 82 RNA-seq supporting reads 4 UHR pooled cells 10 Brain 68 Neuroblastoma 123 bp exon 1 accession from spleen capped 5' end, 1 accession 123 bp exon 56 bp exon 35187 bp [gt-ag] intron 1 GenBank accession (also 5 Primates bodymap) 285 bp exon 1 accession from pancreas 285 bp exon 123 bp exon 123 bp exon 13045 bp [gt-ag] intron 1 GenBank accession 16 RNA-seq supporting reads 2 UHR pooled cells 14 Brain 200 bp exon 1 accession Validated 3' end, 1 accession 200 bp exon Alternative mRNAs are shown aligned from 5' to 3' on a virtual genome where introns have been shrunk to a minimal length. Exon size is proportional to length, intron height reflects the number of cDNAs supporting each intron, the small numbers show the support of the introns in deep sequencing (with details in mouse-over) . Introns of the same color are identical, of different colors are different. 'Good proteins' are pink, partial or not-good proteins are yellow, uORFs are green. 5' cap or3' poly A flags show completeness of the transcript.
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Sequences: click on the numbers to get the DNA back to top
mRNA variant mRNA matching the genome Best predicted protein 5' UTR 3' UTR uORF Upstream sequence Transcription
unit
pre-mRNA
Downstream sequence
aAug10 2742 bp 235 aa 542 bp 1492 bp 24 bp 2kb including Promoter 308193 bp 1kb
bAug10 2551 bp 235 aa 352 bp 1491 bp 282 bp 2kb possibly including promoter 285729 bp 1kb
cAug10 2499 bp 235 aa 299 bp 1492 bp 54 bp 2kb possibly including promoter 285600 bp 1kb
dAug10-unspliced 914 bp 46 aa 741 bp 32 bp 2kb 914 bp 1kb
eAug10 773 bp 40 aa 651 bp 2kb including Promoter 289449 bp 1kb
fAug10 608 bp 96 aa 319 bp 2kb 269382 bp 1kb
gAug10 559 bp 26 aa 380 bp 98 bp 2kb including Promoter 288282 bp 1kb
hAug10 341 bp 36 aa 230 bp 2kb probably including promoter 35528 bp 1kb
iAug10 323 bp 25 aa 67 bp 178 bp 2kb probably including promoter 13368 bp 1kb

Gene neighbors and Navigator on chromosome 3q26.32 back to top
R KCNMB2 D C R P R R R D C R P ZMAT3 100kb 0 sekume, 5 accessions, 2 variants KCNMB2, 75 accessions 9 variants PIK3CA, 141 accessions 7 variants skolobu, 1 accession skorlobu, 1 accession skoylobu, 2 accessions snoylobu, 15 accessions spylobu, 1 accession spawlobu, 1 accession speylobu, 1 accession steylobu, 1 accession dalarbu, 1 accession dylarbu, 1 accession reromo, 3 accessions, 2 variants roromo, 1 accession yaromo, 2 accessions, 2 variants loygawbo, 1 accession keylarbu, 6 accessions garveebo, 2 accessions koylarbu, 3 accessions rylarbu, 1 accession smorsnyby, 1 accession tarlarbu, 1 accession weylarbu, 1 accession worlarbu, 1 accession woylarbu, 1 accession zalarbu, 1 accession chawlarbu, 1 accession sheylarbu, 1 accession glawlarbu, 1 accession nargawbo, 8 accessions klularbu, 2 accessions pleylarbu, 2 accessions slarlarbu, 2 accessions slawlarbu, 1 accession sloylarbu, 1 accession smularbu, 3 accessions smeylarbu, 1 accession smorlarbu, 1 accession snylarbu, 1 accession snawlarbu, 3 accessions snorlarbu, 7 accessions berlawbu, 1 accession tulawbu, 1 accession tolawbu, 3 accessions veelawbu, 1 accession rorgawbo, 1 accession worlawbu, 1 accession plolobu, 2 accessions forgawbo, 1 accession jugawbo, 1 accession sirayo, 1 accession smawlobu, 3 accessions snulobu, 1 accession snawlobu, 1 accession ruromo, 2 accessions, 2 variants jeygawbo, 1 accession kygawbo, 1 accession boylarbu, 2 accessions fularbu, 2 accessions keygawbo, 1 accession koygawbo, 2 accessions feelarbu, 1 accession kularbu, 2 accessions nawlarbu, 1 accession mergawbo, 1 accession pleesnyby, 1 accession pularbu, 1 accession reylarbu, 1 accession vularbu, 1 accession snarsnyby, 1 accession cherlarbu, 1 accession shalarbu, 1 accession blylarbu, 1 accession nogawbo, 6 accessions kleylarbu, 1 accession plarlarbu, 1 accession sposnyby, 1 accession foswerby, 3 accessions nawgawbo, 1 accession snularbu, 1 accession snarlarbu, 1 accession snoylarbu, 1 accession speesnyby, 1 accession spolarbu, 1 accession surayo, 1 accession sparlarbu, 7 accessions swalarbu, 2 accessions swylarbu, 2 accessions spersnyby, 1 accession reygawbo, 1 accession palawbu, 1 accession rulawbu, 3 accessions steesnyby, 1 accession steysnyby, 1 accession sukume, 11 accessions 5 variants fuswerby, 33 accessions 10 variants veewawbo, 1 accession ZMAT3, 357 accessions 4 variants ZOOM IN                D:disease,C:conserved,I:interactions,R:regulation,P:publications         Read more...
Annotated mRNA diagrams back to top
Bibliography:               15 articles in PubMed back to top
? Gene Summary Gene on genome mRNA:.a, .b, .c, .d-u, .e, .f, .g, .h, .i Alternative mRNAs features, proteins, introns, exons, sequences Expression Tissue Function, regulation, related genes DC

To mine knowledge about the gene, please click the 'Gene Summary' or the 'Function, regulation, related genes ' tab at the top of the page. The 'Gene Summary' page includes all we learnt about the gene, functional annotations of neighboring genes, maps, links to other sites and the bibliography. The 'Function, regulation, related genes ' page includes Diseases (D), Pathways, GO annotations, conserved domains (C), interactions (I) reference into function, and pointers to all genes with the same functional annotation.
To compare alternative variants, their summarized annotations, predicted proteins, introns and exons, or to access any sequence, click the 'Alternative mRNAs features' tab. To see a specific mRNA variant diagram, sequence and annotation, click the variant name in the 'mRNA' tab. To examine expression data from all cDNAs clustered in this gene by AceView, click the 'Expression tissue'.

If you know more about this gene, or found errors, please share your knowledge. Thank you !