Crystal structure of the human Tip41 orthologue, TIPRL, reveals a novel fold and a binding site for the PP2Ac C-terminus

DOI: 10.1038/srep30813

Authors: Valéria Scorsato (University of Campinas; Brazilian National;) , Tatiani B. Lima (University of Campinas; Brazilian National Laboratory for Biosciences, Center for Research in Energy and Materials) , Germanna L. Righetto (Brazilian National Laboratory for Biosciences, Center for Research in Energy and Materials) , Nilson I. T. Zanchin (Carlos Chagas Insitute, Oswaldo Cruz Foundation (FIOCRUZ)) , Jose Brandao-Neto (Diamond Light Source) , James Sandy (Diamond Light Source) , Humberto D' Muniz Pereira (São Carlos Institute of Physics, University of São Paulo) , Állan J. R. Ferrari (Institute of Chemistry, University of Campinas) , Fabio C. Gozzo (Institute of Chemistry, University of Campinas) , Juliana Smetana (Brazilian Biosciences National Laboratory) , Ricardo Aparicio (University of Campinas)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Scientific Reports , VOL 6

State: Published (Approved)
Published: August 2016
Diamond Proposal Number(s): 11175

Abstract: TOR signaling pathway regulator-like (TIPRL) is a regulatory protein which inhibits the catalytic subunits of Type 2A phosphatases. Several cellular contexts have been proposed for TIPRL, such as regulation of mTOR signaling, inhibition of apoptosis and biogenesis and recycling of PP2A, however, the underlying molecular mechanism is still poorly understood. We have solved the crystal structure of human TIPRL at 2.15 Å resolution. The structure is a novel fold organized around a central core of antiparallel beta-sheet, showing an N-terminal α/β region at one of its surfaces and a conserved cleft at the opposite surface. Inside this cleft, we found a peptide derived from TEV-mediated cleavage of the affinity tag. We show by mutagenesis, pulldown and hydrogen/deuterium exchange mass spectrometry that this peptide is a mimic for the conserved C-terminal tail of PP2A, an important region of the phosphatase which regulates holoenzyme assembly, and TIPRL preferentially binds the unmodified version of the PP2A-tail mimetic peptide DYFL compared to its tyrosine-phosphorylated version. A docking model of the TIPRL-PP2Ac complex suggests that TIPRL blocks the phosphatase’s active site, providing a structural framework for the function of TIPRL in PP2A inhibition.

Journal Keywords: Biochemistry; x-ray crystallography

Subject Areas: Biology and Bio-materials, Medicine


Instruments: I02-Macromolecular Crystallography

Added On: 15/09/2016 08:00

Documents:
srep30813.pdf

Discipline Tags:

Non-Communicable Diseases Health & Wellbeing Cancer Structural biology Drug Discovery Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)