Scribble associates with two polarity proteins, Lgl2 and Vangl2, via distinct molecular domains.
Scribble (Scrib) is a large multi-domain cytoplasmic protein that was first identified through its requirement for the establishment of epithelial polarity. We tested the hypotheses that Scrib asssociates with the basolateral membrane via multiple domains, binds specific protein partners, and is part of a multimeric complex. We generated a series of EGFP-tagged Scrib fusion proteins and examined their membrane localizations in two types of polarized mammalian epithelial cells using biochemical and morphological approaches. We found that Scrib's Leucine-rich-repeat (LRR) and PDS-95/Discs Large/ZO-1 (PDZ) domains independently associate with the plasma membrane in both cell types. We identified multiple large Scrib complexes, demonstrated that Scrib and the cytoplasmic protein Lethal giant larvae2 (Lgl2) co-IP and that this association occurs via Scrib's LRR domain. Further, this report demonstrates that the membrane protein Vangl2 binds selectively to specific PDZ domains in Scrib. Our identification of Scrib's associations highlights its function in multiple biologic pathways and sets the stage for future identification of more proteins that must interact with Scrib's remaining domains. J. Cell. Biochem. 99: 647-664, 2006. (c) 2006 Wiley-Liss, Inc.
Kallay
Laura M
LM
Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, Maryland 21205, USA.
McNickle
Allison
A
Brennwald
Patrick J
PJ
Hubbard
Ann L
AL
Braiterman
Lelita T
LT
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D016764:Cell Polarity; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004285:Dogs; D006801:Humans; D066298:In Vitro Techniques; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008954:Models, Biological; D046912:Multiprotein Complexes; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D025521:Tumor Suppressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D003598:Cytoskeletal Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D046912:Multiprotein Complexes; D011993:Recombinant Fusion Proteins; C480591:SCRIB protein, human; D025521:Tumor Suppressor Proteins; C468513:VANGL2 protein, human