LAUSR

Regulation of proliferation, apoptosis and cell cycle is crucial for the physiology of germ cells. Their malfunction contributes to infertility and germ cell tumours. Kinesin KIF18A is an important regulator of those processes in animal germ cells. Posttranscriptional regulation of KIF18A has not been extensively explored. Due to the presence of PUM Binding Elements (PBEs), KIF18A mRNA is a potential target of PUMs, RNA-binding proteins of posttranscriptional gene regulation (PTGR). We conducted RNA co-immunoprecipitation combined with RT-qPCR, as well as luciferase reporter assay by applying appropriate luciferase construct encoding the wild type KIF18A 3'UTR, upon PUMs overexpression or knockdown in TCam-2 cells representing human male germ cells. We found that KIF18A is repressed by PUM1 and PUM2. To study how this regulation influences KIF18A function, MTS proliferation assay, apoptosis and cell cycle analysis using flow cytometry was performed upon KIF18A mRNA siRNA knockdown. KIF18A significantly influences proliferation, apoptosis and cell cycle, these effects being opposite to PUM effects. Repression by PUM proteins may represent one of mechanisms influencing KIF18A level in controlling proliferation, cell cycle and apoptosis in TCam-2 cells.