Comparative Interactomes of VRK1 and VRK3 with Their Distinct Roles in the Cell Cycle of Liver Cancer

Abstract

Vaccinia-related kinase 1 (VRK1) and VRK3 are members of the VRK family of serine/threonine kinases and are principally localized in the nucleus. Despite the crucial roles of VRK1/VRK3 in physiology and disease, the molecular and functional interactions of VRK1/VRK3 are poorly understood. Here, we identified over 200 unreported VRK1/VRK3-interacting candidate proteins by affinity purification and LC-MS/MS. The networks of VRK1 and VRK3 interactomes were found to be associated with important biological processes such as the cell cycle, DNA repair, chromatin assembly, and RNA processing. Interactions of interacting proteins with VRK1/VRK3 were confirmed by biochemical assays. We also found that phosphorylations of XRCC5 were regulated by both VRK1/VRK3, and that of CCNB1 was regulated by VRK3. In liver cancer cells and tissues, VRK1/VRK3 were highly upregulated and its depletion affected cell cycle progression in the different phases. VRK3 seemed to affect S phase progression and G2 or M phase entry and exit, whereas VRK1 affects G1/S transition in the liver cancer, which could be explained by different interacting candidate proteins. Thus, this study not only provides a resource for investigating the unidentified functions of VRK1/VRK3, but also an insight into the regulatory roles of VRK1/VRK3 in biological processes.

VRK3 depletion induces cell cycle arrest and metabolic reprogramming of Pontine Diffuse Midline Glioma (DMG)-K27 altered cells

“…While a direct binding to CCNB1 and its phosphorylation by VRK3 was previously reported 16 , we observed here a decrease of CCNB1 in DMG cells after VRK3 KD.…”

“…A previous study of the VRK3 interactome highlighted VRK3 interactions with several chromatin components like histone H1, H2A, H2B type 1 & 2, H3.3, H4 or epigenetic regulators such as Jumonji protein (JARID2), suggesting a role for VRK3 in chromatin organization 16 . We found among VRK3 substrates a significant enrichment for genes involved in telomere organization (FigS3H).…”

“…Moreover, a significant overlap of VRK3 and VRK1 interactomes was reported (40 common interacting proteins) as well as their direct binding to each other 16 . Among the common substrates of VRK1 and VRK3, four were significantly modulated with a threshold of adjusted pvalue of 0.001 after VRK3 KD: three ribosomal proteins (RPL11 - FC 1.41, RPS14 FC 1.35 and RPS15A FC 1.5) and NPM1 exhibiting several functions including H3, H4 and H2B core histone chaperoning function (FC 0.49).…”

“…a significant increase of cells in G1 phase and loss of cells in S phase). Another study reported the inhibition of cell growth following VRK3 silencing 16 . However, it was associated with S phase and G2/M phase arrests in liver cancer.…”

A Survival-Related Competitive Endogenous RNA Network of Prognostic lncRNAs, miRNAs, and mRNAs in Wilms Tumor

“…miR-181a mediates the Wnt/b-catenin pathway to accelerate the progression of colorectal cancer (30), oral squamous cell carcinoma (31), and acute lymphoblastic leukemia (32). The expression of VRK1 directly affects the proliferation of breast cancer and liver cancer (33). CircAGFG1 promotes triplenegative breast cancer progression through the circAGFG1/ miR-195/CCNE1 pathway (34).…”