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Protein

Choline/ethanolamine kinase

Gene

CHKB

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: -Experimental evidence at protein leveli

Functioni

Has a key role in phospholipid biosynthesis. Catalyzes the first step in phosphatidylethanolamine biosynthesis. Phosphorylates ethanolamine, and can also act on choline (in vitro). Has higher activity with ethanolamine. May not significantly contribute to in vivo phosphatidylcholine biosynthesis.1 Publication

Miscellaneous

This protein is produced by a bicistronic gene which also produces the CPT1B protein from a non-overlapping reading frame.

Catalytic activityi

ATP + choline = ADP + phosphocholine.1 Publication
ATP + ethanolamine = ADP + O-phosphoethanolamine.1 Publication

Kineticsi

  1. KM=0.57 mM for choline1 Publication
  2. KM=2.9 mM for ethanolamine1 Publication

    Pathwayi: phosphatidylethanolamine biosynthesis

    This protein is involved in step 1 of the subpathway that synthesizes phosphatidylethanolamine from ethanolamine.
    Proteins known to be involved in the 3 steps of the subpathway in this organism are:
    1. Choline/ethanolamine kinase (CHKB), Ethanolamine kinase 2 (ETNK2), Choline kinase alpha (CHKA), Ethanolamine kinase 1 (ETNK1)
    2. Ethanolamine-phosphate cytidylyltransferase (PCYT2)
    3. Ethanolaminephosphotransferase 1 (SELENOI), Choline/ethanolaminephosphotransferase 1 (CEPT1)
    This subpathway is part of the pathway phosphatidylethanolamine biosynthesis, which is itself part of Phospholipid metabolism.
    View all proteins of this organism that are known to be involved in the subpathway that synthesizes phosphatidylethanolamine from ethanolamine, the pathway phosphatidylethanolamine biosynthesis and in Phospholipid metabolism.

    Sites

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Binding sitei104ATP1
    Binding sitei244ATPBy similarity1
    Binding sitei264ATP1

    Regions

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Nucleotide bindingi75 – 81ATPBy similarity7
    Nucleotide bindingi146 – 152ATP7

    GO - Molecular functioni

    • ATP binding Source: UniProtKB-KW
    • choline kinase activity Source: UniProtKB
    • ethanolamine kinase activity Source: UniProtKB

    GO - Biological processi

    Keywordsi

    Molecular functionKinase, Transferase
    Biological processLipid biosynthesis, Lipid metabolism, Phospholipid biosynthesis, Phospholipid metabolism
    LigandATP-binding, Nucleotide-binding

    Enzyme and pathway databases

    BRENDAi2.7.1.32 2681
    ReactomeiR-HSA-1483191 Synthesis of PC
    R-HSA-1483213 Synthesis of PE
    SABIO-RKiQ9Y259
    UniPathwayiUPA00558; UER00741

    Chemistry databases

    SwissLipidsiSLP:000001747 [Q9Y259-1]

    Names & Taxonomyi

    Protein namesi
    Recommended name:
    Choline/ethanolamine kinase
    Alternative name(s):
    Choline kinase beta (EC:2.7.1.32)
    Short name:
    CK
    Short name:
    CKB
    Choline kinase-like protein
    Ethanolamine kinase (EC:2.7.1.82)
    Short name:
    EK
    Ethanolamine kinase beta
    Short name:
    EKB
    choline/ethanolamine kinase beta
    Short name:
    CKEKB
    Gene namesi
    Name:CHKB
    Synonyms:CHETK, CHKL
    OrganismiHomo sapiens (Human)
    Taxonomic identifieri9606 [NCBI]
    Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
    Proteomesi
    • UP000005640 Componenti: Chromosome 22

    Organism-specific databases

    EuPathDBiHostDB:ENSG00000100288.19
    HGNCiHGNC:1938 CHKB
    MIMi612395 gene
    neXtProtiNX_Q9Y259

    Subcellular locationi

    Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS

    Pathology & Biotechi

    Organism-specific databases

    DisGeNETi1120
    GeneReviewsiCHKB
    MalaCardsiCHKB
    OpenTargetsiENSG00000100288
    Orphaneti280671 Congenital muscular dystrophy due to phosphatidylcholine biosynthesis defect
    PharmGKBiPA26469

    Chemistry databases

    ChEMBLiCHEMBL3112385
    DrugBankiDB00122 Choline

    Polymorphism and mutation databases

    BioMutaiCHKB
    DMDMi6685604

    PTM / Processingi

    Molecule processing

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Initiator methionineiRemovedCombined sources1 Publication
    ChainiPRO_00002062222 – 395Choline/ethanolamine kinaseAdd BLAST394

    Amino acid modifications

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Modified residuei2N-acetylalanineCombined sources1 Publication1

    Keywords - PTMi

    Acetylation

    Proteomic databases

    EPDiQ9Y259
    PaxDbiQ9Y259
    PeptideAtlasiQ9Y259
    PRIDEiQ9Y259
    ProteomicsDBi85662
    85663 [Q9Y259-2]

    PTM databases

    iPTMnetiQ9Y259
    PhosphoSitePlusiQ9Y259

    Expressioni

    Gene expression databases

    BgeeiENSG00000100288
    CleanExiHS_CHKB
    ExpressionAtlasiQ9Y259 baseline and differential
    GenevisibleiQ9Y259 HS

    Organism-specific databases

    HPAiHPA018797

    Interactioni

    Subunit structurei

    Homodimer, and heterodimer with CHKA.1 Publication

    Protein-protein interaction databases

    BioGridi107544, 1 interactor
    IntActiQ9Y259, 1 interactor
    STRINGi9606.ENSP00000384400

    Chemistry databases

    BindingDBiQ9Y259

    Structurei

    Secondary structure

    1395
    Legend: HelixTurnBeta strandPDB Structure known for this area
    Show more details
    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Helixi43 – 57Combined sources15
    Helixi59 – 63Combined sources5
    Helixi66 – 68Combined sources3
    Beta strandi70 – 74Combined sources5
    Turni77 – 79Combined sources3
    Beta strandi82 – 86Combined sources5
    Beta strandi94 – 96Combined sources3
    Beta strandi99 – 105Combined sources7
    Helixi108 – 110Combined sources3
    Helixi113 – 128Combined sources16
    Beta strandi135 – 139Combined sources5
    Beta strandi142 – 146Combined sources5
    Beta strandi149 – 152Combined sources4
    Helixi155 – 159Combined sources5
    Helixi161 – 175Combined sources15
    Helixi187 – 201Combined sources15
    Helixi212 – 215Combined sources4
    Helixi218 – 230Combined sources13
    Beta strandi236 – 239Combined sources4
    Helixi245 – 247Combined sources3
    Beta strandi248 – 252Combined sources5
    Beta strandi255 – 257Combined sources3
    Beta strandi260 – 262Combined sources3
    Helixi265 – 267Combined sources3
    Beta strandi269 – 272Combined sources4
    Helixi273 – 283Combined sources11
    Helixi300 – 302Combined sources3
    Helixi306 – 320Combined sources15
    Turni321 – 323Combined sources3
    Helixi328 – 361Combined sources34
    Beta strandi365 – 368Combined sources4
    Helixi370 – 386Combined sources17

    3D structure databases

    ProteinModelPortaliQ9Y259
    SMRiQ9Y259
    ModBaseiSearch...
    MobiDBiSearch...

    Miscellaneous databases

    EvolutionaryTraceiQ9Y259

    Family & Domainsi

    Region

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Regioni77 – 79Substrate bindingBy similarity3

    Sequence similaritiesi

    Belongs to the choline/ethanolamine kinase family.Curated

    Phylogenomic databases

    eggNOGiKOG2686 Eukaryota
    COG0510 LUCA
    GeneTreeiENSGT00530000062991
    HOGENOMiHOG000041274
    HOVERGENiHBG050943
    InParanoidiQ9Y259
    KOiK14156
    OMAiREQQLHF
    OrthoDBiEOG091G06UK
    PhylomeDBiQ9Y259
    TreeFamiTF313549

    Family and domain databases

    InterProiView protein in InterPro
    IPR026712 Cho/Etha_kinase
    IPR011009 Kinase-like_dom_sf
    PANTHERiPTHR22603:SF35 PTHR22603:SF35, 1 hit
    SUPFAMiSSF56112 SSF56112, 1 hit

    Sequences (2)i

    Sequence statusi: Complete.

    Sequence processingi: The displayed sequence is further processed into a mature form.

    This entry describes 2 isoformsi produced by alternative splicing. AlignAdd to basket

    Isoform 1 (identifier: Q9Y259-1) [UniParc]FASTAAdd to basket

    This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

    « Hide

            10         20         30         40         50
    MAAEATAVAG SGAVGGCLAK DGLQQSKCPD TTPKRRRASS LSRDAERRAY
    60 70 80 90 100
    QWCREYLGGA WRRVQPEELR VYPVSGGLSN LLFRCSLPDH LPSVGEEPRE
    110 120 130 140 150
    VLLRLYGAIL QGVDSLVLES VMFAILAERS LGPQLYGVFP EGRLEQYIPS
    160 170 180 190 200
    RPLKTQELRE PVLSAAIATK MAQFHGMEMP FTKEPHWLFG TMERYLKQIQ
    210 220 230 240 250
    DLPPTGLPEM NLLEMYSLKD EMGNLRKLLE STPSPVVFCH NDIQEGNILL
    260 270 280 290 300
    LSEPENADSL MLVDFEYSSY NYRGFDIGNH FCEWVYDYTH EEWPFYKARP
    310 320 330 340 350
    TDYPTQEQQL HFIRHYLAEA KKGETLSQEE QRKLEEDLLV EVSRYALASH
    360 370 380 390
    FFWGLWSILQ ASMSTIEFGY LDYAQSRFQF YFQQKGQLTS VHSSS
    Length:395
    Mass (Da):45,271
    Last modified:January 23, 2007 - v3
    Checksum:i18367468B22FB9CE
    GO
    Isoform 2 (identifier: Q9Y259-2) [UniParc]FASTAAdd to basket

    The sequence of this isoform differs from the canonical sequence as follows:
         75-127: SGGLSNLLFR...LESVMFAILA → RWEVRGQPLR...WPGGGRGRGR
         128-395: Missing.

    Show »
    Length:127
    Mass (Da):13,506
    Checksum:i1C3DBAB66A5D1637
    GO

    Sequence cautioni

    The sequence AAB03342 differs from that shown. Reason: Erroneous gene model prediction.Curated

    Alternative sequence

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Alternative sequenceiVSP_03424875 – 127SGGLS…FAILA → RWEVRGQPLRCADRGQGSAA GPSGCSMFSPPSCARAWGGA GPAWPGGGRGRGR in isoform 2. CuratedAdd BLAST53
    Alternative sequenceiVSP_034249128 – 395Missing in isoform 2. CuratedAdd BLAST268

    Sequence databases

    Select the link destinations:
    EMBLi
    GenBanki
    DDBJi
    Links Updated
    AB029885 Genomic DNA Translation: BAA82511.1
    AB029886 mRNA Translation: BAA82512.1
    AL096780 mRNA Translation: CAB46629.1
    AL096781 mRNA Translation: CAB46630.1
    CR456419 mRNA Translation: CAG30305.1
    AK314324 mRNA Translation: BAG36972.1
    U62317 Genomic DNA Translation: AAB03342.2 Sequence problems.
    CH471138 Genomic DNA Translation: EAW73573.1
    BC082263 mRNA Translation: AAH82263.1
    BC101488 mRNA Translation: AAI01489.1
    BC113521 mRNA Translation: AAI13522.2
    CCDSiCCDS14099.1 [Q9Y259-1]
    RefSeqiNP_005189.2, NM_005198.4 [Q9Y259-1]
    UniGeneiHs.654827

    Genome annotation databases

    EnsembliENST00000406938; ENSP00000384400; ENSG00000100288 [Q9Y259-1]
    GeneIDi1120
    KEGGihsa:1120
    UCSCiuc003bmv.4 human [Q9Y259-1]

    Keywords - Coding sequence diversityi

    Alternative splicing

    Similar proteinsi

    Entry informationi

    Entry nameiCHKB_HUMAN
    AccessioniPrimary (citable) accession number: Q9Y259
    Secondary accession number(s): A0PJM6, Q13388
    Entry historyiIntegrated into UniProtKB/Swiss-Prot: May 30, 2000
    Last sequence update: January 23, 2007
    Last modified: June 20, 2018
    This is version 147 of the entry and version 3 of the sequence. See complete history.
    Entry statusiReviewed (UniProtKB/Swiss-Prot)
    Annotation programChordata Protein Annotation Program
    DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.

    Miscellaneousi

    Keywords - Technical termi

    3D-structure, Complete proteome, Direct protein sequencing, Reference proteome

    Documents

    1. Human chromosome 22
      Human chromosome 22: entries, gene names and cross-references to MIM
    2. MIM cross-references
      Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
    3. PATHWAY comments
      Index of metabolic and biosynthesis pathways
    4. PDB cross-references
      Index of Protein Data Bank (PDB) cross-references
    5. SIMILARITY comments
      Index of protein domains and families

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