4oeo | pdb_00004oeo
High resolution crystal structure of the unliganded ZO-1 PDZ1 domain
Structural highlights
Function[ZO1_HUMAN] The N-terminal may be involved in transducing a signal required for tight junction assembly, while the C-terminal may have specific properties of tight junctions. The alpha domain might be involved in stabilizing junctions. Plays a role in the regulation of cell migration by targeting CDC42BPB to the leading edge of migrating cells.[1] Publication Abstract from PubMedThe molecular seal between epithelial cells, called the tight junction (TJ), is built by several membrane proteins, with claudins playing the most prominent role. The scaffold proteins of the zonula occludens (ZO) family are required for the correct localization of claudins, and hence formation of the TJ. The intracellular C-terminus of claudins binds to the N-terminal PDZ domain of ZO proteins (PDZ1). Of the 23 identified human claudin proteins, nine possess a tyrosine at the -6 position. Here we show that the claudin affinity for PDZ1 is dependent on the presence or absence of this tyrosine, and that the affinity is reduced if the tyrosine is modified by phosphorylation. The PDZ1 beta2-beta3 loop undergoes a significant conformational change to accommodate this tyrosine. Cell culture experiments support a regulatory role for this tyrosine. Plasticity has been recognized as a critical property of TJs that allow cell remodeling and migration. Our work provides a molecular framework for how TJ plasticity may be regulated. Structural basis of a key factor regulating the affinity between the zonula occludens first PDZ domain and claudins.,Nomme J, Antanasijevic A, Caffrey M, Van Itallie CM, Anderson JM, Fanning AS, Lavie A J Biol Chem. 2015 May 28. pii: jbc.M115.646695. PMID:26023235[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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