dc.contributor.author | Thapa, Chandan Jung | |
dc.date.accessioned | 2021-01-12T13:19:23Z | |
dc.date.available | 2021-01-12T13:19:23Z | |
dc.date.issued | 2021 | |
dc.identifier.isbn | 978-951-39-8486-1 | |
dc.identifier.uri | https://jyx.jyu.fi/handle/123456789/73588 | |
dc.description.abstract | Protein phosphatase 2A (PP2A), the principal Serine/Threonine phosphatase,
functions as a tumor suppressor. In most of the cancers, the PP2A tumor
suppressor activity is inhibited either genetically or by the overexpression of
PP2A inhibitor proteins. It is therapeutically tempting idea to reactivate inhibited
PP2A by small molecule modulators, For that, a better understanding of the
structural and molecular framework of PP2A inhibition is required. In this study,
we have characterized the structural properties of PP2A inhibitor proteins ARPP-
19, ARPP-16, and ENSA, and their interaction with A- and B56-subunits of PP2A
by combining NMR spectroscopy with SAXS and microscale thermophoresis.
The results reveal that both ENSA and ARPP proteins are intrinsically
disordered, but not completely random coil as they have three regions having the
propensity to form transient α-helical structures. Both ARPPs and ENSA were
observed to interact with PP2A A-subunit with modest affinity, whereas, the
interaction with B56-subunit is weak and transient. When ARPP and ENSA
proteins are phosphorylated by Gwl/MAST3 kinase they inhibit PP2A during
mitosis. The phosphomimetic mutants resembling phosphorylation of ARPPs
showed increased affinity towards both A- and B56- subunits, while the
corresponding phosphomimetic mutants of ENSA failed to bind to all other B56
subunits except B56α. Two distinct interaction modes of ARPPs and ENSA with
the PP2A A-subunit were identified. In ARPPs, a second transient α-helix
including its flanking region forms an A-subunit binding motif, whereas ENSA
interacts with A-subunit using an extended region comprising all three transient
α-helical regions. Together, these studies suggest that intrinsically disordered
ARPPs and ENSA bind to PP2A transiently using preformed structural elements.
Altogether, our results provide a crucial step towards the understanding the
molecular bases behind PP2A inhibition, which provide a foundation for the
development of novel and clinically feasible PP2A targeted therapies.
Keywords: ARPP-16/ARPP-19; ENSA; Intrinsically Disordered proteins; NMR,
Protein Phosphatase 2A, SAXS. | en |
dc.format.mimetype | application/pdf | |
dc.language.iso | eng | |
dc.publisher | Jyväskylän yliopisto | |
dc.relation.ispartofseries | JYU dissertations | |
dc.relation.haspart | <b>Artikkeli I:</b> Thapa, Chandan J.; Haataja, Tatu; Pentikäinen, Ulla; Permi, Perttu (2020). 1H, 13C and 15N NMR chemical shift assignments of cAMP-regulated phosphoprotein-19 and -16 (ARPP-19 and ARPP-16). <i>Biomolecular NMR Assignments, 14 (2), 227-231.</i> <a href="https://doi.org/10.1007/s12104-020-09951-w"target="_blank"> DOI: 10.1007/s12104-020-09951-w</a> | |
dc.relation.haspart | <b>Artikkeli II:</b> Chandan Thapa, Pekka Roivas, Tatu Haataja Perttu Permi and Ulla Pentikäinen. Intrinsically disordered PP2A inhibitor proteins’, ARPP-16/19, interaction mechanism with PP2A. <i>Submitted manuscript.</i> | |
dc.relation.haspart | <b>Artikkeli III:</b> Chandan Thapa, Pekka Roivas, Tatu Haataja Perttu Permi and Ulla Pentikäinen. Endogenous PP2A inhibitor protein ENSA, structurally related to ARPP-19, differentially interact with PP2A. <i>Manuscript.</i> | |
dc.rights | In Copyright | |
dc.subject | entsyymit | |
dc.subject | proteiinit | |
dc.subject | inhibiittorit | |
dc.subject | fosforylaatio | |
dc.subject | NMR-spektroskopia | |
dc.subject | ARPP-16/ARPP-19 | |
dc.subject | ENSA | |
dc.subject | intrinsically disordered proteins | |
dc.subject | NMR | |
dc.subject | protein phosphatase 2A | |
dc.subject | SAXS | |
dc.title | Structural insight of PP2A inhibitor proteins and their interaction with PP2A Aand B56-subunits | |
dc.type | Diss. | |
dc.identifier.urn | URN:ISBN:978-951-39-8486-1 | |
dc.relation.issn | 2489-9003 | |
dc.rights.copyright | © The Author & University of Jyväskylä | |
dc.rights.accesslevel | openAccess | |
dc.type.publication | doctoralThesis | |
dc.format.content | fulltext | |
dc.rights.url | http://rightsstatements.org/page/InC/1.0/?language=en | |
dc.date.digitised | | |