1
|
Zaragoza-Gómez A, García-Caffarel E, Cruz-Zamora Y, González J, Anaya-Muñoz VH, Cruz-García F, Juárez-Díaz JA. The Nβ motif of NaTrxh directs secretion as an endoplasmic reticulum transit peptide and variations might result in different cellular targeting. PLoS One 2023; 18:e0287087. [PMID: 37824466 PMCID: PMC10569557 DOI: 10.1371/journal.pone.0287087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 09/29/2023] [Indexed: 10/14/2023] Open
Abstract
Soluble secretory proteins with a signal peptide reach the extracellular space through the endoplasmic reticulum-Golgi conventional pathway. During translation, the signal peptide is recognised by the signal recognition particle and results in a co-translational translocation to the endoplasmic reticulum to continue the secretory pathway. However, soluble secretory proteins lacking a signal peptide are also abundant, and several unconventional (endoplasmic reticulum/Golgi independent) pathways have been proposed and some demonstrated. This work describes new features of the secretion signal called Nβ, originally identified in NaTrxh, a plant extracellular thioredoxin, that does not possess an orthodox signal peptide. We provide evidence that other proteins, including thioredoxins type h, with similar sequences are also signal peptide-lacking secretory proteins. To be a secretion signal, positions 5, 8 and 9 must contain neutral residues in plant proteins-a negative residue in position 8 is suggested in animal proteins-to maintain the Nβ motif negatively charged and a hydrophilic profile. Moreover, our results suggest that the NaTrxh translocation to the endoplasmic reticulum occurs as a post-translational event. Finally, the Nβ motif sequence at the N- or C-terminus could be a feature that may help to predict protein localisation, mainly in plant and animal proteins.
Collapse
Affiliation(s)
- Andre Zaragoza-Gómez
- Departamento de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, UNAM, Ciudad de Mexico, México
- Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Ciudad de Mexico, México
| | - Emilio García-Caffarel
- Departamento de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, UNAM, Ciudad de Mexico, México
| | - Yuridia Cruz-Zamora
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, UNAM, Ciudad de Mexico, México
| | - James González
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, UNAM, Ciudad de Mexico, México
| | - Víctor Hugo Anaya-Muñoz
- Escuela Nacional Estudios Superiores unidad Morelia, Universidad Nacional Autónoma de México, Campus Morelia, Morelia, Michoacán, México
| | - Felipe Cruz-García
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, UNAM, Ciudad de Mexico, México
| | - Javier Andrés Juárez-Díaz
- Departamento de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, UNAM, Ciudad de Mexico, México
| |
Collapse
|
2
|
Torres-Rodríguez MD, González-Segura L, Rodríguez-Sotres R, Juárez-DíaZ JA, Cruz-Zamora Y, Cruz-García F. High resolution crystal structure of NaTrxh from Nicotiana alata and its interaction with the S-RNase. J Struct Biol 2020; 212:107578. [PMID: 32682729 DOI: 10.1016/j.jsb.2020.107578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/11/2020] [Accepted: 07/14/2020] [Indexed: 11/24/2022]
Abstract
Thioredoxins are regulatory proteins that reduce disulfide bonds on target proteins. NaTrxh, which belongs to the plant thioredoxin family h subgroup 2, interacts and reduces the S-RNase enhancing its ribonuclease activity seven-fold, resulting an essential protein for pollen rejection inNicotiana.Here, the crystal structure of NaTrxh at 1.7 Å by X-ray diffraction is reported. NaTrxh conserves the typical fold observed in other thioredoxins from prokaryotes and eukaryotes, but it contains extensions towards both N- and C-termini.The NaTrxh N-terminal extension participates in the reduction of S-RNase, and in the structure reported here, this is orientated towards the reactive site. The interaction between SF11-RNase and the NaTrxh N-terminal was simulated and the short-lived complex observed lasted for a tenth of ns. Moreover, we identified certain amino acids as SF11-RNase-E155 and NaTrxh-M104 as good candidates to contribute to the stability of the complex. Furthermore, we simulated the reduction of the C153-C186 SF11-RNase disulfide bond and observed subtle changes that affect the entire core, which might explain the increase in the ribonuclease activity of S-RNase when it is reduced by NaTrxh.
Collapse
Affiliation(s)
| | - Lilian González-Segura
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México, Cd. Mx 04510, Mexico
| | - Rogelio Rodríguez-Sotres
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México, Cd. Mx 04510, Mexico
| | - Javier Andrés Juárez-DíaZ
- Departamento de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México, Cd. Mx 04510, Mexico
| | - Yuridia Cruz-Zamora
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México, Cd. Mx 04510, Mexico
| | - Felipe Cruz-García
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México, Cd. Mx 04510, Mexico.
| |
Collapse
|
3
|
Torres-Rodríguez MD, Cruz-Zamora Y, Juárez-Díaz JA, Mooney B, McClure BA, Cruz-García F. NaTrxh is an essential protein for pollen rejection in Nicotiana by increasing S-RNase activity. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:1304-1317. [PMID: 32392366 DOI: 10.1111/tpj.14802] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 03/20/2020] [Accepted: 04/28/2020] [Indexed: 06/11/2023]
Abstract
In self-incompatible Solanaceae, the pistil protein S-RNase contributes to S-specific pollen rejection in conspecific crosses, as well as to rejecting pollen from foreign species or whole clades. However, S-RNase alone is not sufficient for either type of pollen rejection. We describe a thioredoxin (Trx) type h from Nicotiana alata, NaTrxh, which interacts with and reduces S-RNase in vitro. Here, we show that expressing a redox-inactive mutant, NaTrxhSS , suppresses both S-specific pollen rejection and rejection of pollen from Nicotiana plumbaginifolia. Biochemical experiments provide evidence that NaTrxh specifically reduces the Cys155 -Cys185 disulphide bond of SC10 -Rnase, resulting in a significant increase of its ribonuclease activity. This reduction and increase in S-RNase activity by NaTrxh helps to explain why S-RNase alone could be insufficient for pollen rejection.
Collapse
Affiliation(s)
- Maria D Torres-Rodríguez
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México. Cd. Mx, 04510, México
| | - Yuridia Cruz-Zamora
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México. Cd. Mx, 04510, México
| | - Javier A Juárez-Díaz
- Departamento de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México. Cd. Mx, 04510, México
| | - Brian Mooney
- Charles W. Gehrke Proteomics Center, University of Missouri, Columbia, MO, 65211, USA
| | - Bruce A McClure
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211, USA
| | - Felipe Cruz-García
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México. Cd. Mx, 04510, México
| |
Collapse
|