Protein
Gene:
PBK (official gene symbol)Other symbol:
PBKCT family:
CT84CT identifier:
CT84Aliases from NCBI:
FLJ14385 , Nori-3 , SPK , TOPKRefSeq :
Protein Names (UNIPROT)
Lymphokine-activated killer T-cell-originated protein kinase
Cellular localization
| Subcellular Localization | Cell type | Methodology | PMID |
|---|---|---|---|
| nucleus and cytoplasm | HeLA cell line (interphase) | Immunofluorescence | 15541388 |
| mitotic spindle | HeLA cell line (mitosis) | Immunofluorescence | 15541388 |
| cytoplasm and occasionally nucleus | mouse primary neuronal precursors | Immunofluorescence | 16291951 |
| around the condensed chromosomes | T47D breast cancer cell line (mitosis) | IHC | 16982762 |
Protein function and interaction
PBK/TOPK in a member of the mitogen-activated protein kinase kinase (MAPKK) family that can be associated and phosphorilates P38 MAPK (Abe et al., 2000 PMID: 10781613). PBK expression has been correlated with the mitotic phase of the cell cycle where it is thought to be phosphorylated during mitosis by cyclinB1/cdk1 complexes (Gaudet et al, 2000 PMID: 10779557; Matsumoto et al., 2004 15541388).
PBK phosphorylates and is phosphorilated by ERK2, in a positive feedback loop, which enhances kinase activity of both proteins (Zhu et al, 2007 PMID: 17631144). PBK expression is regulated by cell cycle-specific transcription factors E2F and CREB/ATF (Nandi et al, 2006 PMID: 16171862).
PBK is able to specifically phosphorylate histone H3 during mitosis,and is supposed to play an important role in cell division and cytokinesis control (Park et al, 2006 PMID: 16982762). PBK makes a kinase-substrate complex with cdk1/cyclin B1 and PRC1 on microtubules during mitosis, enhances the cdk1/cyclin B1-dependent phosphorylation of PRC1 and thereby strongly promotes cytokinesis (Abe et al., 2007 PMID: 17512944).
Yeast two-hybrid analysis identified the interaction between PBK and Raf kinase isoforms (Yuryev et al., 2003 PMID: 12620389). PBK interactes , as well, with JNK-interacting protein 1 and causes an elevation of JNK-interacting protein 1 scaffolding activity, thereby enhancing UVB-induced JNK1 activity (Oh et al., 2007 PMID: 17545598).
Studies have suggested a role for PBK in DNA damage sensing and repair through phosphorylation of H2AX (Zykova et al., 2006 PMID: 17145805) and p38 (Ayllon et al, 2007 PMID: 17160018). As demonstrated by coimmunoprecipitation and yeast two-hybrid analyses, PBK forms a complex with p53. Loss of p53 function as a result of direct physical interaction with PBK is suggested (Nandi et al., 2007 PMID: 17482142).
PBK has a role in neural progenitor proliferation and self-renewal (Dougherty et al, 2005 PMID: 16291951).
