Identification of motives mediating alternative functions of the neomorphic moonlighting TPPP/p25.
The disordered Tubulin Polymerization Promoting Protein (TPPP/p25), a prototype of neomorphic moonlighting proteins, displays physiological and pathological functions by interacting with distinct partners. Here the role of the disordered N- and C-termini straddling a middle flexible segment in the distinct functions of TPPP/p25 was established, and the binding motives responsible for its heteroassociations with tubulin and α-synuclein, its physiological and pathological interacting partner, respectively, were identified. We showed that the truncation of the disordered termini altered the folding state of the middle segment and has functional consequences concerning its physiological function. Double truncation diminished its binding to tubulin/microtubules, consequently the tubulin polymerization/microtubule bundling activities of TPPP/p25 were lost highlighting the role of the disordered termini in its physiological function. In contrast, interaction of TPPP/p25 with α-synuclein was not affected by the truncations and its α-synuclein aggregation promoting activity was preserved, showing that the α-synuclein binding motif is localized within the middle segment. The distinct tubulin and α-synuclein binding motives of TPPP/p25 were also demonstrated at the cellular level: the double truncated TPPP/p25 did not align along the microtubules in contrast to the full length form, while it induced α-synuclein aggregation. The localization of the binding motives on TPPP/p25 were established by specific ELISA experiments performed with designed and synthesized peptides: motives at the 178-187 and 147-156 segments are involved in the binding of tubulin and α-synuclein, respectively. The dissimilarity of these binding motives responsible for the neomorphic moonlighting feature of TPPP/p25 has significant innovative impact in anti-Parkinson drug research.
Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1113 Budapest, Hungary. Electronic address: tokesi.natalia@ttk.mta.hu.
Natália
N
Tőkési
Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1113 Budapest, Hungary. Electronic address: olah.judit@ttk.mta.hu.
Judit
J
Oláh
Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1113 Budapest, Hungary. Electronic address: hlavanda.emma@gmail.com.
Emma
E
Hlavanda
Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1113 Budapest, Hungary. Electronic address: szunyogh@enzim.hu.
Sándor
S
Szunyogh
Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1113 Budapest, Hungary. Electronic address: szaboadel90@gmail.com.
Adél
A
Szabó
Research Group of Peptide Chemistry, Hungarian Academy of Sciences, Eötvös Loránd University, 1117 Budapest, Hungary. Electronic address: babosfruzsi@gmail.com.
Fruzsina
F
Babos
Research Group of Peptide Chemistry, Hungarian Academy of Sciences, Eötvös Loránd University, 1117 Budapest, Hungary. Electronic address: magyar@chem.elte.hu.
Anna
A
Magyar
Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1113 Budapest, Hungary. Electronic address: lehotzky.attila@ttk.mta.hu.
Attila
A
Lehotzky
Department of Organic Chemistry, Institute of Chemistry, Eötvös Loránd University, 1117 Budapest, Hungary. Electronic address: evass@chem.elte.hu.
Elemér
E
Vass
Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1113 Budapest, Hungary. Electronic address: ovadi.judit@ttk.mta.hu.
Judit
J
Ovádi
D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D003412:Cricetulus; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000502:physiology*; D014404:Tubulin / Q000737:chemistry; D051844:alpha-Synuclein / Q000737:chemistry
D009419:Nerve Tissue Proteins; C118136:TPPP protein, human; D014404:Tubulin; D051844:alpha-Synuclein
Binding motives; Neomorphic moonlighting function; TPPP/p25; α-synuclein