Human phosphatase CDC14A is recruited to the cell leading edge to regulate cell migration and adhesion

Abstract

Cell adhesion and migration are highly dynamic biological processes that play important roles in organ development and cancer metastasis. Their tight regulation by small GTPases and protein phosphorylation make interrogation of these key processes of great importance. We now show that the conserved dualspecificity phosphatase human cell-division cycle 14A (hCDC14A) associates with the actin cytoskeleton of human cells. To understand hCDC14A function at this location, we manipulated native loci to ablate hCDC14A phosphatase activity (hCDC14A PD ) in untransformed hTERT-RPE1 and colorectal cancer (HCT116) cell lines and expressed the phosphatase in HeLa FRT T-Rex cells. Ectopic expression of hCDC14A induced stress fiber formation, whereas stress fibers were diminished in hCDC14A PD cells. hCDC14A PD cells displayed faster cell migration and less adhesion than wild-type controls. hCDC14A colocalized with the hCDC14A substrate kidneyand brain-expressed protein (KIBRA) at the cell leading edge and overexpression of KIBRA was able to reverse the phenotypes of hCDC14A PD cells. Finally, we show that ablation of hCDC14A activity increased the aggressive nature of cells in an in vitro tumor formation assay. Consistently, hCDC14A is down-regulated in many tumor tissues and reduced hCDC14A expression is correlated with poorer survival of patients with cancer, to suggest that hCDC14A may directly contribute to the metastatic potential of tumors. Thus, we have uncovered an unanticipated role for hCDC14A in cell migration and adhesion that is clearly distinct from the mitotic and cytokinesis functions of Cdc14/Flp1 in budding and fission yeast.CDC14 | cell migration | cell adhesion | phosphatase

The dNTP triphosphohydrolase activity of SAMHD1 persists during S-phase when the enzyme is phosphorylated at T592

“…We wondered whether Cdc14 or members of the PP1–2 superfamilies were involved in SAMHD1 dephosphorylation during mitotic exit. We compared the timing of pSAMHD1 dephosphorylation in a hRPE-1 line KO for the Cdc14A isoform [30] and in its parental line, but did not detect any difference between the two lines (data not shown). It is therefore unlikely that Cdc14A dephosphorylates SAMHD1 during mitotic exit, even if we cannot exclude some compensatory activity by isoform Cdc14B.…”

Human phosphatase CDC14A regulates actin organization through dephosphorylation of epithelial protein lost in neoplasm

“…In fact, both hCDC14A and eplin are significantly down-regulated in colorectal carcinoma (Fig. 5I) (20). This down-regulation is associated with poor survival in cancer patients (Fig.…”

“…1 E and F and Table S2). Given that hCDC14A associates with the actin cytoskeleton (20) and that hCDC14B is enriched in the nucleus during interphase before associating with the mitotic chromatin ( Fig. S1A), the lack of hCDC14A activity is probably responsible for the hyper-phosphorylation of actin-associated proteins in the RPE1 hCDC14A/B-KO cells.…”

“…However, we recently reported that hCDC14A colocalizes with F-actin at the leading edge of cells and stress fibers where it regulates actin dynamics. This regulation is important for cell migration and cell adhesion (20).…”

“…The only known substrate of hCDC14A that acts within the actin cytoskeleton is the protein Kibra (20,21). However, considering the broad distribution of hCDC14A throughout the actin network, it is highly likely that hCDC14A dephosphorylates additional actin-associated proteins.…”