Human cells lacking CDC14A and CDC14B show differences in ciliogenesis but not in mitotic progression

Abstract

The budding yeast phosphatase Cdc14 has a central role in mitotic exit and cytokinesis. Puzzlingly, a uniform picture for the three human CDC14 paralogues CDC14A, CDC14B and CDC14C in cell cycle control has notemergedto date.Redundant functionsbetweenthe three CDC14 phosphatases could explain this unclear picture. To address the possibility of redundancy,we tested expression ofCDC14 and analysed cell cycle progression of cellswith single and double deletions inCDC14 genes.Our data suggest thatCDC14Cisnot expressed inhumanRPE1 cells, excluding a function in this cell line. Single- and double-knockouts (KO) of CDC14A and CDC14B in RPE1 cells indicate that both phosphatases are not important for the timing of mitotic phases, cytokinesis and cell proliferation. However, cycling CDC14A KO and CDC14BKOcells showaltered ciliogenesis comparedtowild-typecells. The cilia of cycling CDC14A KO cells are longer, whereas CDC14B KO cilia aremore frequent and disassemble faster. In conclusion, this study demonstrates that the cell cycle functions of CDC14 proteins are not conserved between yeast and human cells.