dc.contributor.author |
Espart Herrero, Anna |
dc.contributor.author |
Marín, Maribel |
dc.contributor.author |
Gil-Moreno, Selene |
dc.contributor.author |
Palacios Bonilla, Òscar |
dc.contributor.author |
Amaro Umbert, Francesc |
dc.contributor.author |
Martín-González, Ana |
dc.contributor.author |
Gutiérrez Fernández, Juan Carlos |
dc.contributor.author |
Capdevila Vidal, Mercè |
dc.contributor.author |
Atrian i Ventura, Sílvia |
dc.date |
2015 |
dc.identifier |
https://ddd.uab.cat/record/185276 |
dc.identifier |
urn:10.7150/ijbs.11060 |
dc.identifier |
urn:oai:ddd.uab.cat:185276 |
dc.identifier |
urn:pmid:25798065 |
dc.identifier |
urn:pmcid:PMC4366644 |
dc.identifier |
urn:pmc-uid:4366644 |
dc.identifier |
urn:articleid:14492288v11p456 |
dc.identifier |
urn:wos_id:000443787900014 |
dc.identifier |
urn:oai:egreta.uab.cat:publications/eab8cc11-e94d-4f67-9738-3d000e3c49e5 |
dc.identifier |
urn:scopus_id:84928817540 |
dc.identifier |
urn:oai:pubmedcentral.nih.gov:4366644 |
dc.format |
application/pdf |
dc.language |
eng |
dc.publisher |
|
dc.relation |
Ministerio de Economía y Competitividad BIO2012-39682-C02-01 |
dc.relation |
Ministerio de Economía y Competitividad BES-2010-036553) |
dc.relation |
Ministerio de Economía y Competitividad CGL2008-00317/BOS |
dc.relation |
Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-423 |
dc.relation |
International journal of biological sciences ; Vol. 11 (March 2015), p. 456-471 |
dc.rights |
open access |
dc.rights |
Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. |
dc.rights |
https://creativecommons.org/licenses/by-nc/3.0/ |
dc.subject |
Metallothionein |
dc.subject |
Functional differentiation |
dc.subject |
Metal specificity |
dc.subject |
Zinc |
dc.subject |
Copper |
dc.subject |
Tetrahymena thermophila |
dc.title |
Hints for metal-preference protein sequence determinants : different metal binding features of the five Tetrahymena thermophila metallothioneins |
dc.type |
Article |
dc.description.abstract |
The metal binding preference of metallothioneins (MTs) groups them in two extreme subsets, the Zn/Cd- and the Cu-thioneins. Ciliates harbor the largest MT gene/protein family reported so far, including 5 paralogs that exhibit relatively low sequence similarity, excepting MTT2 and MTT4. In Tetrahymena thermophila, three MTs (MTT1, MTT3 and MTT5) were considered Cd-thioneins and two (MTT2 and MTT4) Cu-thioneins, according to gene expression inducibility and phylogenetic analysis. In this study, the metal-binding abilities of the five MTT proteins were characterized, to obtain information about the folding and stability of their cognate- and non-cognate metal complexes, and to characterize the T. thermophila MT system at protein level. Hence, the five MTTs were recombinantly synthesized as Zn²⁺ -, Cd²⁺ - or Cu⁺ -complexes, which were analyzed by electrospray mass spectrometry (ESI-MS), circular dichroism (CD), and UV-vis spectrophotometry. Among the Cd-thioneins, MTT1 and MTT5 were optimal for Cd²⁺ coordination, yielding unique Cd₁₇ and Cd₈ complexes, respectively and Cd- complexes, respectively. When binding Zn²⁺, they rendered a mixture of Zn-species. Only MTT5 was capable to coordinate Cu⁺, although yielding heteronuclear Zn-, Cu-species or highly unstable Cu-homometallic species. MTT3 exhibited poor binding abilities both for Cd²⁺ and for Cu⁺, and although not optimally, it yielded the best result when coordinating Zn²⁺. The two Cu-thioneins, MTT2 and MTT4 isoforms formed homometallic Cu-complexes (major Cu-MTT) upon synthesis in Cu-supplemented hosts. Contrarily, they were unable to fold into stable Cd-complexes, while Zn-MTT species were only recovered for MTT4 (major Zn-MTT4). Thus, the metal binding preferences of the five T. thermophila MTs correlate well with their previous classification as Cd- and Cu-thioneins, and globally, they can be classified from Zn/Cd- to Cu-thioneins according to the gradation: MTT1>MTT5>MTT3>MTT4>MTT2. The main mechanisms underlying the evolution and specialization of the MTT metal binding preferences may have been internal tandem duplications, presence of doublet and triplet Cys patterns in Zn/Cd-thioneins, and optimization of site specific amino acid determinants (Lys for Zn/Cd- and Asn for Cu-coordination). |