PKNOX1 explained

PBX/Knotted 1 Homeobox 1 (PKNOX1) is a protein that in humans is encoded by the PKNOX1 gene.^{[1] [2]}

An important paralog of this gene is PKNOX2.

Function

PKNOX1 belongs to the three amino acid loop extension (TALE) class of homeodomain transcription factors that form transcriptionally active complexes involved in development and organogenesis. PKNOX1 is essential for embryogenesis, but it can also act as a tumor suppressor in adulthood.^[3]

See also: Homeobox.

Further reading

• Allen TD, Zhu YX, Hawley TS, Hawley RG . TALE homeoproteins as HOX11-interacting partners in T-cell leukemia . Leukemia & Lymphoma . 39 . 3–4 . 241–56 . October 2000 . 11342305 . 10.3109/10428190009065824 . 27407074 .
• Chang CP, Shen WF, Rozenfeld S, Lawrence HJ, Largman C, Cleary ML . Pbx proteins display hexapeptide-dependent cooperative DNA binding with a subset of Hox proteins . Genes & Development . 9 . 6 . 663–74 . March 1995 . 7729685 . 10.1101/gad.9.6.663 . free .
• Maruyama K, Sugano S . Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides . Gene . 138 . 1–2 . 171–4 . January 1994 . 8125298 . 10.1016/0378-1119(94)90802-8 .
• Hillier LD, Lennon G, Becker M, Bonaldo MF, Chiapelli B, Chissoe S, Dietrich N, DuBuque T, Favello A, Gish W, Hawkins M, Hultman M, Kucaba T, Lacy M, Le M, Le N, Mardis E, Moore B, Morris M, Parsons J, Prange C, Rifkin L, Rohlfing T, Schellenberg K, Bento Soares M, Tan F, Thierry-Meg J, Trevaskis E, Underwood K, Wohldman P, Waterston R, Wilson R, Marra M . 6 . Generation and analysis of 280,000 human expressed sequence tags . Genome Research . 6 . 9 . 807–28 . September 1996 . 8889549 . 10.1101/gr.6.9.807 . free .
• Phelan ML, Featherstone MS . Distinct HOX N-terminal arm residues are responsible for specificity of DNA recognition by HOX monomers and HOX.PBX heterodimers . The Journal of Biological Chemistry . 272 . 13 . 8635–43 . March 1997 . 9079695 . 10.1074/jbc.272.13.8635 . free .
• Chen H, Rossier C, Nakamura Y, Lynn A, Chakravarti A, Antonarakis SE . Cloning of a novel homeobox-containing gene, PKNOX1, and mapping to human chromosome 21q22.3 . Genomics . 41 . 2 . 193–200 . April 1997 . 9143494 . 10.1006/geno.1997.4632 .
• LeBrun DP, Matthews BP, Feldman BJ, Cleary ML . The chimeric oncoproteins E2A-PBX1 and E2A-HLF are concentrated within spherical nuclear domains . Oncogene . 15 . 17 . 2059–67 . October 1997 . 9366523 . 10.1038/sj.onc.1201367 . free .
• Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K, Suyama A, Sugano S . Construction and characterization of a full length-enriched and a 5'-end-enriched cDNA library . Gene . 200 . 1–2 . 149–56 . October 1997 . 9373149 . 10.1016/S0378-1119(97)00411-3 .
• Berthelsen J, Zappavigna V, Mavilio F, Blasi F . Prep1, a novel functional partner of Pbx proteins . The EMBO Journal . 17 . 5 . 1423–33 . March 1998 . 9482739 . 1170490 . 10.1093/emboj/17.5.1423 .
• Berthelsen J, Zappavigna V, Ferretti E, Mavilio F, Blasi F . The novel homeoprotein Prep1 modulates Pbx-Hox protein cooperativity . The EMBO Journal . 17 . 5 . 1434–45 . March 1998 . 9482740 . 1170491 . 10.1093/emboj/17.5.1434 .
• Green NC, Rambaldi I, Teakles J, Featherstone MS . A conserved C-terminal domain in PBX increases DNA binding by the PBX homeodomain and is not a primary site of contact for the YPWM motif of HOXA1 . The Journal of Biological Chemistry . 273 . 21 . 13273–9 . May 1998 . 9582372 . 10.1074/jbc.273.21.13273 . free .
• Berthelsen J, Kilstrup-Nielsen C, Blasi F, Mavilio F, Zappavigna V . The subcellular localization of PBX1 and EXD proteins depends on nuclear import and export signals and is modulated by association with PREP1 and HTH . Genes & Development . 13 . 8 . 946–53 . April 1999 . 10215622 . 316640 . 10.1101/gad.13.8.946 .
• Jacobs Y, Schnabel CA, Cleary ML . Trimeric association of Hox and TALE homeodomain proteins mediates Hoxb2 hindbrain enhancer activity . Molecular and Cellular Biology . 19 . 7 . 5134–42 . July 1999 . 10373562 . 84356 . 10.1128/mcb.19.7.5134 .
• Knoepfler PS, Bergstrom DA, Uetsuki T, Dac-Korytko I, Sun YH, Wright WE, Tapscott SJ, Kamps MP . 6 . A conserved motif N-terminal to the DNA-binding domains of myogenic bHLH transcription factors mediates cooperative DNA binding with pbx-Meis1/Prep1 . Nucleic Acids Research . 27 . 18 . 3752–61 . September 1999 . 10471746 . 148632 . 10.1093/nar/27.18.3752 .
• Kömüves LG, Shen WF, Kwong A, Stelnicki E, Rozenfeld S, Oda Y, Blink A, Krishnan K, Lau B, Mauro T, Largman C . 6 . Changes in HOXB6 homeodomain protein structure and localization during human epidermal development and differentiation . Developmental Dynamics . 218 . 4 . 636–47 . August 2000 . 10906782 . 10.1002/1097-0177(2000)9999:9999<::AID-DVDY1014>3.0.CO;2-I . free .
• Okada Y, Matsuura E, Nagai R, Sato T, Watanabe A, Morita I, Doi T . PREP1, MEIS1 homolog protein, regulates PF4 gene expression . Biochemical and Biophysical Research Communications . 305 . 1 . 155–9 . May 2003 . 12732210 . 10.1016/S0006-291X(03)00718-6 .

Notes and References

1. Berthelsen J, Viggiano L, Schulz H, Ferretti E, Consalez GG, Rocchi M, Blasi F . PKNOX1, a gene encoding PREP1, a new regulator of Pbx activity, maps on human chromosome 21q22.3 and murine chromosome 17B/C . Genomics . 47 . 2 . 323–4 . January 1998 . 9479508 . 10.1006/geno.1997.5086 .
2. Web site: Entrez Gene: PKNOX1 PBX/knotted 1 homeobox 1. 2017-09-07. 2010-12-05. https://web.archive.org/web/20101205081110/http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene. live.
3. Purushothaman D, Blasi F . The genetics and the molecular functions of the PREP1 homeodomain transcription factor . The International Journal of Developmental Biology . 62 . 11–12 . 819–825 . 2018 . 30604851 . 10.1387/ijdb.180238fb . free .