Abstract

Simple SummaryCyclin-dependent kinases (CDKs), as biological macromolecules, play key regulatory roles in the cell cycle process. Cyclin-dependent kinase-5 (CDK5) is part of the CDK family; however, its effect on cell cycle progression is controversial and the mechanism remains unclear. In this article, we identified a homologous gene of the Cyclin-dependent kinase family,BmCDK5,in the silkworm,Bombyx mori. We proved that theBmCDK5gene can regulate the cell cycle and promote cell proliferation in BmNS cells. Furthermore, we demonstrated that BmCDK5 can interact with BmCNN, and that they both affect cytoskeleton morphology but do not induce changes in microtubule protein expression; they can also promote cell proliferation.AbstractThe ordered cell cycle is important to the proliferation and differentiation of living organisms. Cyclin-dependent kinases (CDKs) perform regulatory functions in different phases of the cell cycle process to ensure order. We identified a homologous gene of the Cyclin-dependent kinase family,BmCDK5, inBombyx mori. BmCDK5 contains the STKc_CDK5 domain. TheBmCDK5gene was highly expressed in S phase. Overexpression of theBmCDK5gene accelerates the process of the cell cycle’s mitotic period (M) and promotes cell proliferation; knocking out theBmCDK5gene inhibited cell proliferation. Furthermore, we identified a protein, BmCNN, which can interact with BmCDK5 and represents the same express patterns as theBmCDK5gene in the cell cycle phase and the spatial-temporal expression ofB. mori. This study revealed that BmCDK5 and BmCNN play roles in promoting cell proliferation and regulating cytoskeleton morphology, but do not induce expression changes in microtubule protein. Therefore, our findings provide a new insight; theBmCDK5gene has a regulatory effect on the cell cycle and proliferation ofB. mori, which is presumably due to the interaction between BmCDK5 and BmCNN regulating changes in the cytoskeleton.Keywords:Cyclin-dependent kinase 5;Bombyx mo