Unveiling the Movement of RanBP1 During the Cell Cycle and Its Interaction with a Cyclin-Dependent Kinase (CDK) in Plants

Author(s):Show less -

Thome, Vanessa ; Ferreira, Pedro B. ; Lubini, Greice ; Nogueira, Fernanda M. ; Strini, Edward J. ; Pinoti, Vitor F. ; Cruz, Joelma O. ; San Martin, Juca A. B. ; Quiapim, Andrea C. ; Dasilva, Luis L. P. ; Goldman, Maria Helena S.

• Document type: Journal article
• Source: INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES; v. 26, n. 1, p. 23-pg., 2025-01-01.

Abstract

In the Nicotiana tabacum flower development study, we identified SCI1 (Stigma/style Cell-cycle Inhibitor 1), a regulator of cell proliferation. SCI1 interacts with NtCDKG;2 (N. tabacum Cyclin-Dependent Kinase G;2), a homolog of human CDK11, which is responsible for RanGTP-dependent microtubule stabilization, regulating spindle assembly rate. In a Y2H screening of a cDNA library using NtCDKG;2 as bait, a RanBP1 (Ran-Binding Protein 1) was revealed as its interaction partner. RanBP1 is an essential regulatory protein of the RanGTPase system, contributing to the formation of the Ran gradient, which modulates different important cellular processes. RanBP1 is crucial in the nuclear import/export machinery during interphase and spindle checkpoint formation during cell division. These processes are well studied in animals, but very little is known about them in plants. We confirmed NtCDKG;2 and NtRanBP1 interaction by pairwise Y2H and characterized the localization of both proteins during plant cell division. We demonstrated the presence of NtRanBP1 in the cytoplasm during interphase and its nuclear arrest at mitosis onset. Meanwhile, we showed that NtCDKG;2 is localized in the mitotic spindle during cell division, indicating an analogous function to the human CDK11. We propose that the phosphorylation of the nuclear export signal at RanBP1 by NtCDKG;2 may be responsible for the reported nuclear arrest. (AU)

• FAPESP's process: 12/50562-2 - Study of SCI1 and its protein-protein interactions that result in cell cycle inhibition
• Grantee: Maria Helena de Souza Goldman
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/24774-1 - The importance of the SCI1 gene in the floral meristem, its transcriptional regulation and evolutionary conservation
• Grantee: Maria Helena de Souza Goldman
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/20486-3 - Deciphering SCI1, its expression during flower development and mechanisms of action for the control of cell proliferation
• Grantee: Maria Helena de Souza Goldman
• Support Opportunities: Regular Research Grants
• FAPESP's process: 23/12687-2 - Study of floral development and root growth kinetics in transgenic plants with altered levels of NtRH35 (NtDDX35) expression
• Grantee: Fernanda Mayara Nogueira
• Support Opportunities: Scholarships in Brazil - Support Program for Fixating Young Doctors