Affinity and distance dependence of SLiM-mediated dephosphorylation by protein phosphatase 1
- 1Aarhus University
Abstract
Protein phosphatases counterbalance kinases by dephosphorylating phospho-proteins to regulate signaling pathways. But unlike kinases, their shallow catalytic groove has limited selectivity for the phospho-peptide motifs. Phosphatases such as protein phosphatase-1 (PP1) recognize their substrates through short linear motifs (SLiMs) within intrinsically disordered regions, yet the mechanism of SLiM-mediated recruitment remains unclear. We developed an intrinsically disordered phospho-protein substrate to enable quantitative modelling of tethered PP1 catalysis by varying SLiM affinity and distance. We show that a PP1-binding SLiM linked to a phospho-peptide by a flexible spacer is sufficient to enhance dephosphorylation. Dephosphorylation occurs most efficiently at a spacing of 20-30 residues, in agreement with predictions from theoretical polymer models. Low micromolar dissociation constants are most efficient for dephosphorylation, which can be modelled numerically as a trade-off between substrate binding and substrate inhibition. Bivalent SLiMs enhance or decrease catalysis depending on the combined affinity. Together, these results define a quantitative and generalizable framework for how linear motifs direct dephosphorylation by PP1.
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BibTeX
@misc{lande2026affinity,
title = {{Affinity and distance dependence of SLiM-mediated dephosphorylation by protein phosphatase 1}},
author = {E. S. Lande and M. Kjaergaard},
howpublished = {bioRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.09.750541},
url = {https://www.biorxiv.org/content/10.64898/2026.09.09.750541v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Affinity and distance dependence of SLiM-mediated dephosphorylation by protein phosphatase 1
AU - E. S. Lande
AU - M. Kjaergaard
PY - 2026
DA - 2026/09/09
PB - bioRxiv
DO - 10.64898/2026.09.09.750541
UR - https://www.biorxiv.org/content/10.64898/2026.09.09.750541v1
AB - Protein phosphatases counterbalance kinases by dephosphorylating phospho-proteins to regulate signaling pathways. But unlike kinases, their shallow catalytic groove has limited selectivity for the phospho-peptide motifs. Phosphatases such as protein phosphatase-1 (PP1) recognize their substrates through short linear motifs (SLiMs) within intrinsically disordered regions, yet the mechanism of SLiM-mediated recruitment remains unclear. We developed an intrinsically disordered phospho-protein substrate to enable quantitative modelling of tethered PP1 catalysis by varying SLiM affinity and distance. We show that a PP1-binding SLiM linked to a phospho-peptide by a flexible spacer is sufficient to enhance dephosphorylation. Dephosphorylation occurs most efficiently at a spacing of 20-30 residues, in agreement with predictions from theoretical polymer models. Low micromolar dissociation constants are most efficient for dephosphorylation, which can be modelled numerically as a trade-off between substrate binding and substrate inhibition. Bivalent SLiMs enhance or decrease catalysis depending on the combined affinity. Together, these results define a quantitative and generalizable framework for how linear motifs direct dephosphorylation by PP1.
ER -