PKNOX2

PBX/Knotted 1 Homeobox 2 (PKNOX2) protein belongs to the three amino acid loop extension (TALE) class of homeodomain proteins, and is encoded by PKNOX2 gene in humans. The protein regulates the transcription of other genes and affects anatomical development.[5]

PKNOX2
Identifiers
Aliases	PKNOX2, PREP2, PBX/knotted 1 homeobox 2
External IDs	OMIM: 613066 MGI: 2445415 HomoloGene: 32527 GeneCards: PKNOX2
Gene location (Human) Chr. Chromosome 11 (human)[1] Band 11q24.2 Start 125,164,687 bp[1] End 125,433,389 bp[1]
Gene location (Mouse) Chr. Chromosome 9 (mouse)[2] Band 9|9 A4 Start 36,890,982 bp[2] End 37,147,407 bp[2]
Gene ontology Molecular function • DNA binding • sequence-specific DNA binding • actin filament binding • actin monomer binding • RNA polymerase II regulatory region sequence-specific DNA binding • GO:0001200, GO:0001133, GO:0001201 DNA-binding transcription factor activity, RNA polymerase II-specific Cellular component • cytoplasm • microtubule cytoskeleton • actin cytoskeleton • cell nucleus • nucleoplasm • intercellular bridge Biological process • regulation of transcription from RNA polymerase II promoter • regulation of transcription, DNA-templated Sources:Amigo / QuickGO
Orthologs
Species	Human	Mouse
Entrez	63876	208076
Ensembl	ENSG00000165495	ENSMUSG00000035934
UniProt	Q96KN3	Q8BG99
RefSeq (mRNA)	NM_022062	NM_001029838 NM_148950
RefSeq (protein)	NP_001369252 NP_001369253 NP_001369254 NP_001369255 NP_001369256 NP_001369257 NP_001369258 NP_001369259 NP_001369260 NP_001369261 NP_001369262 NP_001369263 NP_001369264 NP_001369265 NP_001369266 NP_001369267 NP_001369268 NP_001369269 NP_001369270	NP_001025009 NP_683752
Location (UCSC)	Chr 11: 125.16 – 125.43 Mb	Chr 9: 36.89 – 37.15 Mb
PubMed search	[3]	[4]
Wikidata
View/Edit Human View/Edit Mouse

Function

PKNOX2 protein regulates expression of other genes by binding to DNA in a sequence-specific manner, i.e. to specific DNA sequences. It binds to unique DNA recognition motifs, acting as a nuclear transcription factor.[6] The nuclear transcription factor is a protein that regulates transcription of genetic information from DNA to messenger RNA. Other functions of PKNOX2 include actin filament binding. An important paralog of the PKNOX2 gene is PKNOX1.

Structure

PKNOX2 belongs to the three amino acid loop extension (TALE) class of homeodomain proteins. This class is characterized by a 3-amino acid extension between alpha helix 1 and 2 in the homeodomain.[7]

Homeodomain proteins are sequence-specific transcription factors that share a highly conserved DNA binding domain and play a crucial role in cell proliferation, differentiation and death.[7]

Clinical significance

In a 2014 review article of the genome-wide association findings of alcohol dependence, the researchers concluded that based on functional analysis (demonstration of a cause-effect relation),[8] genetic variants related to the PKNOX2 gene may play a role in alcohol dependence risk, albeit a minor role comparing to the role played by the genes located in the alcohol dehydrogenase cluster.[9]

See also

• Homeobox
• Binding to specific DNA sequences
• Human PKNOX2 genome location and PKNOX2 gene details page in the UCSC Genome Browser.

References

1. GRCh38: Ensembl release 89: ENSG00000165495 - Ensembl, May 2017
2. GRCm38: Ensembl release 89: ENSMUSG00000035934 - Ensembl, May 2017
3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
5. Imoto I, Sonoda I, Yuki Y, Inazawa J (September 2001). "Identification and characterization of human PKNOX2, a novel homeobox-containing gene". Biochemical and Biophysical Research Communications. 287 (1): 270–6. doi:10.1006/bbrc.2001.5578. PMID 11549286.
6. Fognani C, Kilstrup-Nielsen C, Berthelsen J, Ferretti E, Zappavigna V, Blasi F (May 2002). "Characterization of PREP2, a paralog of PREP1, which defines a novel sub-family of the MEINOX TALE homeodomain transcription factors". Nucleic Acids Research. 30 (9): 2043–51. doi:10.1093/nar/30.9.2043. PMC 113854. PMID 11972344.
7. "PKNOX2 PBX/knotted 1 homeobox 2 - Gene - GTR - NCBI". www.ncbi.nlm.nih.gov. National Center for Biotechnology Information. Retrieved 31 August 2020. Homeodomain proteins are sequence-specific transcription factors that share a highly conserved DNA-binding domain and play fundamental roles in cell proliferation, differentiation, and death. PKNOX2 belongs to the TALE (3-amino acid loop extension) class of homeodomain proteins characterized by a 3-amino acid extension between alpha helices 1 and 2 within the homeodomain This article incorporates text from this source, which is in the public domain.
8. Iwata BA, Dozier CL (2008). "Clinical application of functional analysis methodology". Behavior Analysis in Practice. 1 (1): 3–9. doi:10.1007/BF03391714. PMC 2846577. PMID 22477673.
9. Zuo L, Lu L, Tan Y, Pan X, Cai Y, Wang X, et al. (2014). "Genome-wide association discoveries of alcohol dependence". The American Journal on Addictions. 23 (6): 526–39. doi:10.1111/j.1521-0391.2014.12147.x. PMC 4187224. PMID 25278008.