1. Structural studies of the TPLATE complex
Supervisor: Konstantinos Tripsianes, Ph.D.
The TPLATE complex (TPC) is essential for endocytosis in plants, yet it is evolutionary lost from yeasts and animals, pointing to the fact that endocytosis is mechanistically regulated differently. In plants, the complex consists of eight subunits, four of which constitute the core (TPLATE, TASH3, TML and LOLITA), two proteins which presumably overarch the core (TWD40-1 and TWD40-2) and two proteins which are homologs of the yeast ARP2/3 activator Pan1 (AtEH1/Pan1 and AtEH2/Pan1). The association of the AtEH/Pan1 subunits to the other TPC subunits is plant specific and these subunits are also presumed to link the canonical AP-2 endocytic complex to TPC. How these subunits are connected to the other subunits of AP-2 and TPC is however completely unknown.
The AtEH/Pan1 proteins have an unstructured C-terminal tail domain which holds several peptide motifs known to interact with AP-2 appendage domains (WxxF; FxxFxxF/L and DPF motifs) as well as repetitions of unknown motifs. The aim of this research project is to establish the interaction mode between the motifs and the appendage domains of AP-2 and TPC via NMR. In a next step, additional structural techniques will be employed to study the high-order TPLATE complex. Recombinant appendage domains are currently being produced in the Van Damme lab, Ghent, Belgium, and tested in mutant complementation assays. His lab will contribute to the project with cellular assays for a better functional understanding of the structural findings.
RG: Konstantinos Tripsianes Research Group
Keywords: TPLATE complex, TPC, AP-2, appendage domains, NMR, structural techniques