Basolateral Protein Scribble Provides Phosphatase PP1 to a Signaling Network Maintaining Apicobasal Polarity
Ontology highlight
ABSTRACT: Scribble, a member of the LAP protein family, contributes to the apicobasal polarity
(ABP) of epithelial cells. The LAP unique region (LUR) of these proteins is essential for
ABP function, and includes a highly conserved Leucine Reach Repeat (LRR) domain.
Here we study how the LRR domain of Scribble maintains ABP. We show that its
concave surface participates in three types of mutually exclusive interactions 1.
homodimerization serving as an auto-inhibitory mechanism, 2. interactions with a
diverse set of polarity proteins, such as Llgl1, Llgl2, EPB41L2 and EPB41L5, which
produce distinct multiprotein complexes, and 3. a direct interaction with the protein
phosphatase, PP1, which forms a dimeric LRR domain-PP1 complex. Our results suggest
that the latter complex maintains PP1 in the basolateral cell cortex in close proximity to
PP1 targets. Such organization generates a dynamic network where PP1 could be
immediately dispatched from the Scribble-PP1 complex to particular protein ligands.
This mechanism for controlling dephosphorylation kinetics of phosphorylated proteins
could be universal for all members of the LAP protein family, which includes Erbin,
Lano, and the neuron-specific protein, Densin-180.
INSTRUMENT(S): LTQ Orbitrap Elite
ORGANISM(S): Homo Sapiens (ncbitaxon:9606)
SUBMITTER: Sergey M Troyanovsky
PROVIDER: MSV000088094 | MassIVE |
SECONDARY ACCESSION(S): PXD028463
REPOSITORIES: MassIVE
ACCESS DATA