Serine/threonine-protein kinase PLK4 also known as polo-like kinase 4 is an enzyme that in humans is encoded by the PLK4gene.[1] The Drosophila homolog is SAK, the C elegans homolog is zyg-1, and the Xenopus homolog is Plx4.[2]
PLK4 encodes a member of the polo family of serine/threonine protein kinases. The protein localizes to centrioles—complex microtubule-based structures found in centrosomes—and regulates centriole duplication during the cell cycle.[1] Overexpression of PLK4 results in centrosome amplification, and knockdown of PLK4 results in loss of centrosomes.[3][4]
Structure
PLK4 contains an N-terminal kinase domain (residues 12-284) and a C-terminal localization domain (residues 596-898).[5] Other polo-like kinase members contain 2 C-terminal polo box domains (PBD). PLK4 contains these 2 domains in addition to a third PBD, which facilitates oligomerization, targeting, and promotes trans-autophosphorylation, limiting centriole duplication to once per cell cycle.[5]
As a cancer drug target
Inhibitors of the enzymatic activity PLK4 have potential in the treatment of cancer.[6] The PLK4 inhibitorR1530 down regulates the expression of mitotic checkpoint kinase BubR1 that in turn leads to polyploidy rendering cancer cells unstable and more sensitive to cancer chemotherapy. Furthermore, normal cells are resistant to the polyploidy inducing effects of R1530.[7]
Another PLK4 inhibitor, CFI-400945 has demonstrated efficacy in animal models of breast and ovarian cancer.[8][9]
Another PLK4 inhibitor, centrinone, has been reported to deplete centrioles in human and other vertebrate cell types, which resulted in a p53-dependent cell cycle arrest in G1.[10] Inhibition of PLK4 using a chemical genetic strategy has validated this p53-dependent cell cycle arrest in G1.[11]
PLK4 was also identified as a potential therapeutic target for malignant rhabdoid tumors, medulloblastomas and possibly, other embryonal tumors of the brain.[12][13][14]
Interactions and substrates
Documented PLK4 substrates include STIL, GCP6,[15] Hand1,[16][17] Ect2,[18] FBXW5,[19] and itself (via autophosphorylation). Autophosphorylation of PLK4 results in ubiquitination and subsequent destruction by the proteasome.[20][21]
↑Mason J, Wei S, Luo X, Nadeem V, Kiarash R, Huang P, Awrey D, Leung G, Beletskaya I, Feher M, Forrest B, Laufer R, Sampson P, Li SW, Liu Y, Lang Y, Pauls H, Mak T, Pan JG. "Inhibition of Polo-like kinase 4 as an anti-cancer strategy". Abstract LB-215. Cancer Research. pp. LB-215.
↑Tovar C, Higgins B, Deo D, Kolinsky K, Liu JJ, Heimbrook DC, Vassilev LT (August 2010). "Small-molecule inducer of cancer cell polyploidy promotes apoptosis or senescence: Implications for therapy". Cell Cycle. 9 (16): 3364–75. doi:10.4161/cc.9.16.12732. PMID20814247.
↑Sredni ST, Suzuki M, Yang JP, Topczewski J, Bailey AW, Gokirmak T, Gross JN, de Andrade A, Kondo A, Piper DR, Tomita T (November 2017). "A functional screening of the kinome identifies the Polo-like kinase 4 as a potential therapeutic target for malignant rhabdoid tumors, and possibly, other embryonal tumors of the brain". Pediatric Blood & Cancer. 64 (11): n/a–n/a. doi:10.1002/pbc.26551. PMID28398638.
↑Sredni ST, Bailey AW, Bsc AS, Hashizume R, He X, Louis N, Gokimak T, Piper DR, Watterson DM (November 2017). "Inhibition of polo-like kinase 4 (PLK4): a new therapeutic option for rhabdoid tumors and pediatric medulloblastoma". Oncotarget. 5 (0). doi:10.18632/oncotarget.22704.
↑Bahtz R, Seidler J, Arnold M, Haselmann-Weiss U, Antony C, Lehmann WD, Hoffmann I (January 2012). "GCP6 is a substrate of Plk4 and required for centriole duplication". Journal of Cell Science. 125 (Pt 2): 486–96. doi:10.1242/jcs.093930. PMID22302995.
↑Martindill DM, Risebro CA, Smart N, Franco-Viseras Mdel M, Rosario CO, Swallow CJ, Dennis JW, Riley PR (October 2007). "Nucleolar release of Hand1 acts as a molecular switch to determine cell fate". Nature Cell Biology. 9 (10): 1131–41. doi:10.1038/ncb1633. PMID17891141.
↑Hudson JW, Kozarova A, Cheung P, Macmillan JC, Swallow CJ, Cross JC, Dennis JW (March 2001). "Late mitotic failure in mice lacking Sak, a polo-like kinase". Current Biology. 11 (6): 441–6. doi:10.1016/s0960-9822(01)00117-8. PMID11301255.
↑Puklowski A, Homsi Y, Keller D, May M, Chauhan S, Kossatz U, Grünwald V, Kubicka S, Pich A, Manns MP, Hoffmann I, Gönczy P, Malek NP (July 2011). "The SCF-FBXW5 E3-ubiquitin ligase is regulated by PLK4 and targets HsSAS-6 to control centrosome duplication". Nature Cell Biology. 13 (8): 1004–9. doi:10.1038/ncb2282. PMID21725316.
↑Cunha-Ferreira I, Bento I, Pimenta-Marques A, Jana SC, Lince-Faria M, Duarte P, Borrego-Pinto J, Gilberto S, Amado T, Brito D, Rodrigues-Martins A, Debski J, Dzhindzhev N, Bettencourt-Dias M (November 2013). "Regulation of autophosphorylation controls PLK4 self-destruction and centriole number". Current Biology. 23 (22): 2245–54. doi:10.1016/j.cub.2013.09.037. PMID24184099.
↑Rual JF, Venkatesan K, Hao T, Hirozane-Kishikawa T, Dricot A, Li N, Berriz GF, Gibbons FD, Dreze M, Ayivi-Guedehoussou N, Klitgord N, Simon C, Boxem M, Milstein S, Rosenberg J, Goldberg DS, Zhang LV, Wong SL, Franklin G, Li S, Albala JS, Lim J, Fraughton C, Llamosas E, Cevik S, Bex C, Lamesch P, Sikorski RS, Vandenhaute J, Zoghbi HY, Smolyar A, Bosak S, Sequerra R, Doucette-Stamm L, Cusick ME, Hill DE, Roth FP, Vidal M (October 2005). "Towards a proteome-scale map of the human protein-protein interaction network". Nature. 437 (7062): 1173–8. doi:10.1038/nature04209. PMID16189514.
Further reading
Kleylein-Sohn J, Westendorf J, Le Clech M, Habedanck R, Stierhof YD, Nigg EA (August 2007). "Plk4-induced centriole biogenesis in human cells". Developmental Cell. 13 (2): 190–202. doi:10.1016/j.devcel.2007.07.002. PMID17681131.
Bettencourt-Dias M, Rodrigues-Martins A, Carpenter L, Riparbelli M, Lehmann L, Gatt MK, Carmo N, Balloux F, Callaini G, Glover DM (December 2005). "SAK/PLK4 is required for centriole duplication and flagella development". Current Biology. 15 (24): 2199–207. doi:10.1016/j.cub.2005.11.042. PMID16326102.
Habedanck R, Stierhof YD, Wilkinson CJ, Nigg EA (November 2005). "The Polo kinase Plk4 functions in centriole duplication". Nature Cell Biology. 7 (11): 1140–6. doi:10.1038/ncb1320. PMID16244668.
Rual JF, Venkatesan K, Hao T, Hirozane-Kishikawa T, Dricot A, Li N, Berriz GF, Gibbons FD, Dreze M, Ayivi-Guedehoussou N, Klitgord N, Simon C, Boxem M, Milstein S, Rosenberg J, Goldberg DS, Zhang LV, Wong SL, Franklin G, Li S, Albala JS, Lim J, Fraughton C, Llamosas E, Cevik S, Bex C, Lamesch P, Sikorski RS, Vandenhaute J, Zoghbi HY, Smolyar A, Bosak S, Sequerra R, Doucette-Stamm L, Cusick ME, Hill DE, Roth FP, Vidal M (October 2005). "Towards a proteome-scale map of the human protein-protein interaction network". Nature. 437 (7062): 1173–8. doi:10.1038/nature04209. PMID16189514.
Barrios-Rodiles M, Brown KR, Ozdamar B, Bose R, Liu Z, Donovan RS, Shinjo F, Liu Y, Dembowy J, Taylor IW, Luga V, Przulj N, Robinson M, Suzuki H, Hayashizaki Y, Jurisica I, Wrana JL (March 2005). "High-throughput mapping of a dynamic signaling network in mammalian cells". Science. 307 (5715): 1621–5. doi:10.1126/science.1105776. PMID15761153.
Macmillan JC, Hudson JW, Bull S, Dennis JW, Swallow CJ (October 2001). "Comparative expression of the mitotic regulators SAK and PLK in colorectal cancer". Annals of Surgical Oncology. 8 (9): 729–40. doi:10.1007/s10434-001-0729-6. PMID11597015.
Yamashita Y, Kajigaya S, Yoshida K, Ueno S, Ota J, Ohmine K, Ueda M, Miyazato A, Ohya K, Kitamura T, Ozawa K, Mano H (October 2001). "Sak serine-threonine kinase acts as an effector of Tec tyrosine kinase". The Journal of Biological Chemistry. 276 (42): 39012–20. doi:10.1074/jbc.M106249200. PMID11489907.
Schultz SJ, Nigg EA (October 1993). "Identification of 21 novel human protein kinases, including 3 members of a family related to the cell cycle regulator nimA of Aspergillus nidulans". Cell Growth & Differentiation. 4 (10): 821–30. PMID8274451.