Serine/threonine-protein kinase Chk2 - O96017 (CHK2_HUMAN)

 

Protein Feature View of PDB entries mapped to a UniProtKB sequence  

  • Number of PDB entries for O96017: 38
 
Function
Serine/threonine-protein kinase which is required for checkpoint-mediated cell cycle arrest, activation of DNA repair and apoptosis in response to the presence of DNA double-strand breaks. May also negatively regulate cell cycle progression during unperturbed cell cycles. Following activation, phosphorylates numerous effectors preferentially at the consensus sequence [L-X-R-X-X-S/T]. Regulates cell cycle checkpoint arrest through phosphorylation of CDC25A, CDC25B and CDC25C, inhibiting their activity. Inhibition of CDC25 phosphatase activity leads to increased inhibitory tyrosine phosphorylation of CDK-cyclin complexes and blocks cell cycle progression. May also phosphorylate NEK6 which is involved in G2/M cell cycle arrest. Regulates DNA repair through phosphorylation of BRCA2, enhancing the association of RAD51 with chromatin which promotes DNA repair by homologous recombination. Also stimulates the transcription of genes involved in DNA repair (including BRCA2) through the phosphorylation and activation of the transcription factor FOXM1. Regulates apoptosis through the phosphorylation of p53/TP53, MDM4 and PML. Phosphorylation of p53/TP53 at 'Ser-20' by CHEK2 may alleviate inhibition by MDM2, leading to accumulation of active p53/TP53. Phosphorylation of MDM4 may also reduce degradation of p53/TP53. Also controls the transcription of pro-apoptotic genes through phosphorylation of the transcription factor E2F1. Tumor suppressor, it may also have a DNA damage-independent function in mitotic spindle assembly by phosphorylating BRCA1. Its absence may be a cause of the chromosomal instability observed in some cancer cells. Promotes the CCAR2-SIRT1 association and is required for CCAR2-mediated SIRT1 inhibition (PubMed:25361978). (data source: UniProt  )
Catalytic Activity

ATP + a protein = ADP + a phosphoprotein.

(data source: UniProt  )
Subunit structure
Homodimer. Homodimerization is part of the activation process but the dimer may dissociate following activation. Interacts with PML. Interacts with TP53. Interacts with RB1; phosphorylates RB1. Interacts with BRCA1. Interacts (phosphorylated at Thr-68) with MDC1; requires ATM-mediated phosphorylation of CHEK2. Interacts with TP53BP1; modulates CHEK2 phosphorylation at Thr-68 in response to ionizing radiation. Interacts with CDC25A; phosphorylates CDC25A and mediates its degradation in response to ionizing radiation. Interacts with CUL1; mediates CHEK2 ubiquitination and regulation. Interacts with CDKN2AIP. Interacts (via protein kinase domain) with CCAR2 (via N-terminus). Interacts with SIRT1. (data source: UniProt  )
Organism (common name): Human
Isoforms: 13, currently showing only the 'canonical' sequence.
Full screen
Display Options
Zoom
min
max
Sort by
Color by
 
Legend
The Protein Feature View requires a browser that supports SVG (Scalable Vector Graphics). Mouse over tracks and labels for more information.
Data origin/color codes
The vertical color bar on the left side indicates data provenance.
Data in green originates from UniProtKB  
Data in yellow originates from Pfam  , by interacting with the HMMER3 web site  
Data in purple originates from Phosphosite  .
Data in orange originates from the SCOP   (version 1.75) and SCOPe   (version 2.04) classifications.
Data in grey has been calculated using BioJava  . Protein disorder predictions are based on JRONN (Troshin, P. and Barton, G. J. unpublished), a Java implementation of RONN  
  • Red: potentially disorderd region
  • Blue: probably ordered region.
Hydropathy has been calculated using a sliding window of 15 residues and summing up scores from standard hydrophobicity tables.
  • Red: hydrophobic
  • Blue: hydrophilic.
Data in lilac represent the genomic exon structure projected onto the UniProt sequence.
Data in blue originates from PDB
  • Secstruc: Secondary structure projected from representative PDB entries onto the UniProt sequence.
Data in red indicates combined ranges of Homology Models from SBKB   and the Protein Model Portal  
The PDB to UniProt mapping is based on the data provided by the EBI SIFTS project. See also Velankar et al., Nucleic Acids Research 33, D262-265 (2005).
Organism icons generated by flaticon.com under CC BY. The authors are: Freepik, Icons8, OCHA, Scott de Jonge.