[PDF][PDF] Establishment of par-polarized cortical domains via phosphoregulated membrane motifs

MJ Bailey, KE Prehoda - Developmental cell, 2015 - cell.com
MJ Bailey, KE Prehoda
Developmental cell, 2015cell.com
The Par polarity complex creates mutually exclusive cortical domains in diverse animal cells.
Activity of the atypical protein kinase C (aPKC) is a key output of the Par complex as
phosphorylation removes substrates from the Par domain. Here, we investigate how diverse,
apparently unrelated Par substrates couple phosphorylation to cortical displacement. Each
protein contains a basic and hydrophobic (BH) motif that interacts directly with phospholipids
and also overlaps with aPKC phosphorylation sites. Phosphorylation alters the electrostatic …
Summary
The Par polarity complex creates mutually exclusive cortical domains in diverse animal cells. Activity of the atypical protein kinase C (aPKC) is a key output of the Par complex as phosphorylation removes substrates from the Par domain. Here, we investigate how diverse, apparently unrelated Par substrates couple phosphorylation to cortical displacement. Each protein contains a basic and hydrophobic (BH) motif that interacts directly with phospholipids and also overlaps with aPKC phosphorylation sites. Phosphorylation alters the electrostatic character of the sequence, inhibiting interaction with phospholipids and the cell cortex. We searched for overlapping BH and aPKC phosphorylation site motifs (i.e., putative phosphoregulated BH motifs) in several animal proteomes. Candidate proteins with strong PRBH signals associated with the cell cortex but were displaced into the cytoplasm by aPKC. These findings demonstrate a potentially general mechanism for exclusion of proteins from the Par cortical domain in polarized cells.
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