Conserved and Divergent Modes of Substrate Interaction Define Selective Localizations and Functions of a Cdc14 Phosphatase

Cdc14 phosphatases share conserved catalytic domains and enzymatic mechanisms. Despite functioning in disparate biological processes across eukaryotes, Cdc14 enzymes localize to analogous cellular structures from yeast to human cells. It remains unclear, however, whether modes of substrate recognition and intracellular targeting mechanisms are conserved among Cdc14 orthologs. Here, we address these questions using Clp1, the Schizosaccharomyces pombe Cdc14 phosphatase. We show that Clp1 utilizes a conserved hydrophobic pocket, originally defined in Saccharomyces cerevisiae Cdc14, to engage a subset of interactors, although unlike many S. cerevisiae Cdc14 substrates, these targets show a broad hydrophobic interaction motif spectrum. Disruption of the hydrophobic pocket selectively abrogates certain Clp1 interactions, localizations, and functions, while others are retained. Moreover, we find that nucleolar localization depends upon both hydrophobic pocket-mediated interactions and the Clp1 non-catalytic C-terminus. Our results suggest that Cdc14 uses multiple mechanisms to engage substrates and achieve proper spatial distribution for its diverse functions.