Available structures
PDBOrtholog search: PDBe RCSB
AliasesMELK, HPK38, maternal embryonic leucine zipper kinase
External IDsOMIM: 607025 MGI: 106924 HomoloGene: 32111 GeneCards: MELK
EC number2.7.10.2
RefSeq (mRNA)


RefSeq (protein)


Location (UCSC)Chr 9: 36.57 – 36.68 MbChr 4: 44.3 – 44.36 Mb
PubMed search[3][4]
View/Edit HumanView/Edit Mouse

Maternal embryonic leucine zipper kinase (MELK) is an enzyme that in humans is encoded by the MELK gene.[5][6][7] MELK is a serine/threonine kinase belonging to the family of AMPK/Snf1 protein kinases. MELK was first identified present as maternal mRNA in mouse embryos.[8] MELK expression is elevated in a number of cancers and is an active research target for pharmacological inhibition.[9]

MELK was previously believed to be essential for cancer cell proliferation. However, recent research using CRISPR has demonstrated that MELK is fully dispensable for cancer cell growth, casting doubt on the rationale for targeting this protein in patients. The results are dependent on the experimental design. Therefore, there is a need for further research. [10][11][12][13]


MELK has been shown to interact with CDC25B.[14]


  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000165304Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000035683Ensembl, 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. ^ Nagase T, Seki N, Ishikawa K, Tanaka A, Nomura N (February 1996). "Prediction of the coding sequences of unidentified human genes. V. The coding sequences of 40 new genes (KIAA0161-KIAA0200) deduced by analysis of cDNA clones from human cell line KG-1". DNA Research. 3 (1): 17–24. doi:10.1093/dnares/3.1.17. PMID 8724849.
  6. ^ Heyer BS, Warsowe J, Solter D, Knowles BB, Ackerman SL (June 1997). "New member of the Snf1/AMPK kinase family, Melk, is expressed in the mouse egg and preimplantation embryo". Molecular Reproduction and Development. 47 (2): 148–56. doi:10.1002/(SICI)1098-2795(199706)47:2<148::AID-MRD4>3.0.CO;2-M. PMID 9136115. S2CID 27882565.
  7. ^ "Entrez Gene: MELK maternal embryonic leucine zipper kinase".
  8. ^ Heyer BS, Kochanowski H, Solter D (August 1999). "Expression of Melk, a new protein kinase, during early mouse development". Developmental Dynamics. 215 (4): 344–51. doi:10.1002/(SICI)1097-0177(199908)215:4<344::AID-AJA6>3.0.CO;2-H. PMID 10417823.
  9. ^ Gray D, Jubb AM, Hogue D, Dowd P, Kljavin N, Yi S, et al. (November 2005). "Maternal embryonic leucine zipper kinase/murine protein serine-threonine kinase 38 is a promising therapeutic target for multiple cancers". Cancer Research. 65 (21): 9751–61. doi:10.1158/0008-5472.CAN-04-4531. PMID 16266996.
  10. ^ Lin A, Giuliano CJ, Sayles NM, Sheltzer JM (March 2017). "CRISPR/Cas9 mutagenesis invalidates a putative cancer dependency targeted in on-going clinical trials". eLife. 6. doi:10.7554/eLife.24179. PMC 5365317. PMID 28337968.
  11. ^ Huang HT, Seo HS, Zhang T, Wang Y, Jiang B, Li Q, et al. (September 2017). "MELK is not necessary for the proliferation of basal-like breast cancer cells". eLife. 6. doi:10.7554/eLife.26693. PMC 5605198. PMID 28926338.
  12. ^ Giuliano CJ, Lin A, Smith JC, Palladino AC, Sheltzer JM (February 2018). "MELK expression correlates with tumor mitotic activity but is not required for cancer growth". eLife. 7. doi:10.7554/eLife.32838. PMC 5805410. PMID 29417930.
  13. ^ Settleman J, Sawyers CL, Hunter T (February 2018). "Challenges in validating candidate therapeutic targets in cancer". eLife. 7. doi:10.7554/eLife.32402. PMC 5805407. PMID 29417929.
  14. ^ Davezac N, Baldin V, Blot J, Ducommun B, Tassan JP (October 2002). "Human pEg3 kinase associates with and phosphorylates CDC25B phosphatase: a potential role for pEg3 in cell cycle regulation". Oncogene. 21 (50): 7630–41. doi:10.1038/sj.onc.1205870. PMID 12400006.

Further reading