Suppression and overexpression of ubiquitin extension protein S27a affects cell proliferation and in vitro regeneration in Nicotiana benthamiana

Uri Hanania; Margarita Velcheva; Nachman Sahar; Moshe Flaishman; Etti Or; Oded Dgani; Avihai Perl

doi:10.1016/j.plantsci.2009.01.019

Suppression and overexpression of ubiquitin extension protein S27a affects cell proliferation and in vitro regeneration in Nicotiana benthamiana

Plant Sci. 2009 Apr;176(4):566-74. doi: 10.1016/j.plantsci.2009.01.019. Epub 2009 Feb 6.

Authors

Uri Hanania¹, Margarita Velcheva¹, Nachman Sahar¹, Moshe Flaishman¹, Etti Or¹, Oded Dgani¹, Avihai Perl²

Affiliations

¹ Department of Fruit Tree Sciences, Institute of Plant Sciences, Agricultural Research Organization, P.O. Box 6, Bet-Dagan 50250, Israel.
² Department of Fruit Tree Sciences, Institute of Plant Sciences, Agricultural Research Organization, P.O. Box 6, Bet-Dagan 50250, Israel. Electronic address: vhlperl@agri.gov.il.

PMID: 26493147
DOI: 10.1016/j.plantsci.2009.01.019

Abstract

Ubiquitin is a highly conserved 76-amino-acid protein found in all eukaryotic cells. Ubiquitin's expression is encoded and expressed as multimeric head-to-tail repeats (polyubiquitins) that are post-translationally cleaved into monomers, or fused with ribosomal proteins S27a and L40. S27a is highly expressed in meristematic tissues, pollen and ovules and its ubiquitin moiety is thought to act as a chaperone in ribosome biogenesis prior to cleavage. This study suggests that the ribosomal protein S27a plays a critical role in the allocation of meristematic cells that differentiate into lateral structures such as leaves and flowers. S27a was also found to regulate floral meristem development, possibly through the control of cell proliferation as well as cell identity. Overexpression of S27a was correlated with increased proliferation of undifferentiated cells and arrest of morphologically "normal" shoot and leaf development. The ubiquitin moiety did not affect the localization of S27a, but it did affect its protein level: expression of S27a without the ubiquitin moiety caused a severe reduction in S27a protein level.

Keywords: N. benthamiana; Shoot apical meristem; Tobacco rattle virus; Ubiquitin extension S27a.