Transmembrane Complexes of DAP12 Crystallized in Lipid Membranes Provide Insights into Control of Oligomerization in Immunoreceptor Assembly

Autor: Konstantin Knoblich, Soohyung Park, Mariam Lutfi, Leonie van ’t Hag, Charlotte E. Conn, Shane A. Seabrook, Janet Newman, Peter E. Czabotar, Wonpil Im, Matthew E. Call, Melissa J. Call
Jazyk: angličtina
Rok vydání: 2015
Předmět:
Zdroj: Cell Reports, Vol 11, Iss 8, Pp 1184-1192 (2015)
Druh dokumentu: article
ISSN: 2211-1247
DOI: 10.1016/j.celrep.2015.04.045
Popis: The membrane-spanning α helices of single-pass receptors play crucial roles in stabilizing oligomeric structures and transducing biochemical signals across the membrane. Probing intermolecular transmembrane interactions in single-pass receptors presents unique challenges, reflected in a gross underrepresentation of their membrane-embedded domains in structural databases. Here, we present two high-resolution structures of transmembrane assemblies from a eukaryotic single-pass protein crystallized in a lipidic membrane environment. Trimeric and tetrameric structures of the immunoreceptor signaling module DAP12, determined to 1.77-Å and 2.14-Å resolution, respectively, are organized by the same polar surfaces that govern intramembrane assembly with client receptors. We demonstrate that, in addition to the well-studied dimeric form, these trimeric and tetrameric structures are made in cells, and their formation is competitive with receptor association in the ER. The polar transmembrane sequences therefore act as primary determinants of oligomerization specificity through interplay between charge shielding and sequestration of polar surfaces within helix interfaces.
Databáze: Directory of Open Access Journals