ANKK1

Ankyrin repeat and kinase domain containing 1
Identifiers
SymbolsANKK1 ; PKK2
External IDsOMIM: 608774 HomoloGene: 18258 IUPHAR: 1932 ChEMBL: 5547 GeneCards: ANKK1 Gene
EC number2.7.11.1
Orthologs
SpeciesHumanMouse
Entrez255239244859
EnsemblENSG00000170209ENSMUSG00000032257
UniProtQ8NFD2Q8BZ25
RefSeq (mRNA)NM_178510NM_172922
RefSeq (protein)NP_848605NP_766510
Location (UCSC)Chr 11:
113.26 – 113.27 Mb		Chr 9:
49.42 – 49.43 Mb
PubMed search

Ankyrin repeat and kinase domain containing 1 (ANKK1) also known as protein kinase PKK2 or sugen kinase 288 (SgK288) is an enzyme that in humans is encoded by the ANKK1 gene. The ANKK1 is a member of an extensive family of the Ser/Thr protein kinase family, and protein kinase superfamily involved in signal transduction pathways.

Clinical significance

This gene contains a single nucleotide polymorphism that causes an amino acid substitution within the 11th of 12 ankyrin repeats of ANKK1 (Glu713Lys of 765 residues). This polymorphism, which is commonly referred to Taq1A, was previously believed to be located in the promoter region of the DRD2 gene, since the polymorphism is proximal to the DRD2 gene and can influence DRD2 receptor expression.[1] It is now known to be located in the coding region of the ANKK1 gene which controls the synthesis of dopamine in the brain.[2] The A1 allele is associated with increased activity of striatal L-amino acid decarboxylase.[3]

A1+ allele

Given that the A1+ allele is associated with dissocial personality disorder, one may infer that the allele is also associated with narcissistic personality disorder and histrionic personality disorder. However, these predictions have not yet been empirically verified.

A1+ genotype frequencies

European population estimates for A1+ genotype frequencies range from 20.8 to 43.4% (National Center of Biotechnology Information (NCBI), identification number rs1800497).[8]

Addictive behaviors

The ANKK1 gene is closely linked to dopamine receptor D2 (DRD2) on chromosome band 11q23.1.[9] The A1 allele of the Taq1A polymorphism (rs1800497T), is located ≈10kb downstream of the dopamine receptor DRD2 gene. Dopamine (DA) is a neurotransmitter in the brain, which controls feeling of wellbeing. This sensation results from the interaction of dopamine and other neurotransmitters such as serotonin, the opioids, and other brain chemicals. Dopamine increases the motivation for food cravings and appetite mediation.[10]

This single-nucleotide polymorphism (SNP) is a mutation that actually occurs in the gene encoding for the kinase ANKK1, where it causes a non-conservative amino acid substitution often called a missense mutation. This type of mutation is not always deleterious, but experts have considered it somewhat ambiguous because it can be associated to variety of diseases. The DRD2/ANKK1-Taq1A polymorphism modulates the density of the DRD2 dopamine receptors. Carriers of the A1 allele have shown up to 30%[11] reduced receptors capacity, being the main reason why this lack of dopamine receptors predisposes individuals with this SNP mutation to seek for addictive behaviors or substances to compensate this deficiency in the dopaminergic system; such as binge eating (e.g. fat, refined carbohydrates, salt, caffeine, etc.), compulsive and impulsive behaviours (e.g. sexual activity, gambling and use of alcohol, drugs, opiates, tobacco etc.).[12]

The Reward Deficiency Syndrome (RDS) involves the pleasures or reward mechanisms that rely on dopamine. The result of this deficiency is based on the genetic makeup; this helps explain how certain simple genetic anomalies can give rise to complex aberrant behaviours as the ones mentioned previously. The A1 allelic prevalence has been reported to be significantly higher in obese individuals that in lean subjects,[11] moreover, individuals with increased body mass index (BMI) (BMI >30 kg/m²) have fewer DRD2 dopamine receptors. Investigators have also suggested that hormonal mechanism may underline a gender difference in the ability to suppress hunger in relation to this SNP, which may contribute to the greater incidence of obesity in women compared to men.[13] However, authors have pointed out that A1 carriers have difficulty in learning from negative feedback in a reinforcement-learning task and are less efficient at learning to avoid actions that have negative consequences.

References

  1. ↑ Lucht M, Rosskopf D (July 2008). "Comment on "Genetically determined differences in learning from errors"". Science 321 (5886): 200; author reply 200. doi:10.1126/science.1155372. PMID 18621654.
  2. ↑ Neville MJ, Johnstone EC, Walton RT (June 2004). "Identification and characterization of ANKK1: a novel kinase gene closely linked to DRD2 on chromosome band 11q23.1". Hum. Mutat. 23 (6): 540–5. doi:10.1002/humu.20039. PMID 15146457.
  3. ↑ Laakso A, Pohjalainen T, Bergman J, Kajander J, Haaparanta M, Solin O, Syvälahti E, Hietala J (June 2005). "The A1 allele of the human D2 dopamine receptor gene is associated with increased activity of striatal L-amino acid decarboxylase in healthy subjects". Pharmacogenet. Genomics 15 (6): 387–91. doi:10.1097/01213011-200506000-00003. PMID 15900211.
  4. ↑ Lawford B, Young R, Noble EP, Crawford D, Rowell J, Shadforth S, Ritchie T, Zhang X, Cooksley GE (January 1999). "The DRD2A₁allele: a behavioural genetic risk factor in hepatitis C infection of persistent drug abusers". Addict Biol 4 (1): 61–6. doi:10.1080/13556219971858. PMID 20575771.
  5. ↑ Lu RB, Lee JF, Huang SY, Lee SY, Chang YH, Kuo PH, Chen SL, Chen SH, Chu CH, Lin WW, Wu PL, Ko HC (November 2010). "Interaction between ALDH2*1*1 and DRD2/ANKK1 TaqI A1A1 genes may be associated with antisocial personality disorder not co-morbid with alcoholism". Addict Biol 17: 865–874. doi:10.1111/j.1369-1600.2010.00268.x. PMID 21070510.
  6. ↑ Ponce G, Hoenicka J, Jiménez-Arriero MA, Rodríguez-Jiménez R, Aragüés M, Martín-Suñé N, Huertas E, Palomo T (August 2008). "DRD2 and ANKK1 genotype in alcohol-dependent patients with psychopathic traits: association and interaction study". Br J Psychiatry 193 (2): 121–5. doi:10.1192/bjp.bp.107.041582. PMID 18669994.
  7. ↑ Blum K, Braverman ER, Wu S, Cull JG, Chen TJ, Gill J, Wood R, Eisenberg A, Sherman M, Davis KR, Matthews D, Fischer L, Schnautz N, Walsh W, Pontius AA, Zedar M, Kaats G, Comings DE (May 1997). "Association of polymorphisms of dopamine D2 receptor (DRD2), and dopamine transporter (DAT1) genes with schizoid/avoidant behaviors (SAB)". Mol. Psychiatry 2 (3): 239–46. doi:10.1038/sj.mp.4000261. PMID 9152988.
  8. ↑ "rs1800497". Reference SNP(refSNP) Cluster Report. United States National Center for Biotechnology Information.
  9. ↑ Neville MJ, Johnstone EC, Walton RT (22 April 2004). "Identification and characterization of ANKK1: A novel kinase gene closely linked to DRD2 on chromosome band 11q23.1". Human Mutation 23 (6): 540–545. doi:10.1002/humu.20039. PMID 15146457.
  10. ↑ Stice E, Spoor S, Bohon C, Small DM (17 October 2008). "Relation Between Obesity and Blunted Striatal Response to Food Is Moderated by TaqIA A1 Allele". Science 322 (5900): 449–452. doi:10.1126/science.1161550. PMID 18927395.
  11. ↑ 11.0 11.1 Ariza M, Garolera M, Jurado MA, Garcia-Garcia I, Hernan I, Sánchez-Garre C, Vernet-Vernet M, Sender-Palacios MJ, Marques-Iturria I, Pueyo R, Segura B, Narberhaus A (25 July 2012). "Dopamine Genes (DRD2/ANKK1-TaqA1 and DRD4-7R) and Executive Function: Their Interaction with Obesity". PLoS ONE 7 (7): e41482. doi:10.1371/journal.pone.0041482. PMID 22848508.
  12. ↑ Blum K, Oscar-Berman M, Barh D, Giordano J, Gold M (2013). "Dopamine Genetics and Function in Food and Substance Abuse". Journal of Genetic Syndromes & Gene Therapy 4 (1): 121. doi:10.4172/2157-7412.1000121. PMID 23543775.
  13. ↑ Heber D, Carpenter CL (19 April 2011). "Addictive Genes and the Relationship to Obesity and Inflammation". Molecular Neurobiology 44 (2): 160–165. doi:10.1007/s12035-011-8180-6. PMID 21499988.

External links