The invention relates to phosphatase ligands and polyligands. In particular, the invention relates to ligands, homopolyligands, and heteropolyligands that modulate PP1 activity. The ligands and polyligands are utilized as research tools or as therapeutics. The invention includes linkage of the ligands, homopolyligands, and heteropolyligands to a cellular localization signal, epitope tag and/or a reporter. The invention also includes polynucleotides encoding the ligands and polyligands.