Finally, we discuss the effects of pathogen-derived proteins on plant host ubiquitin system proteins. Specifically, we review how the ubiquitin system affects expression of genes or abundance of proteins important for determining when a plant flowers (focusing on FLOWERING LOCUS C, FRIGIDA, and CONSTANS), highlight some recent studies on how seed size is affected by the ubiquitin system, and discuss how the ubiquitin system affects proteins involved in pathogen or effector recognition with details on recent studies on FLS2 and SNC1, respectively, as examples. Here we summarize three agronomic traits influenced by ubiquitination: induction of flowering, seed size, and pathogen responses.
The ubiquitin system affects plant health, reproduction, and responses to the environment, processes which impact important agronomic traits. In a single vascular plant species, the ubiquitin system consists of thousands of different proteins involved in attaching ubiquitin to substrates, recognizing or processing ubiquitinated proteins, or constituting or regulating the 26S proteasome.
Our results demonstrated that the C-terminal region of OsCDC48 was essential for maintaining the full ATPase activity and OsCDC48/48E complex might function in form of heteromultimers to modulate cellular processes and plant survival in rice. Overexpression of OsCDC48–psd128 resulted in differential expression of AAA-ATPase associated genes leading to increased total ATPase activity, accumulation of reactive oxygen species and decreased plant tiller numbers while overexpression of OsCDC48 also resulted in differential expression of AAA-ATPase associated genes leading to increased total ATPase activity, but increased plant tiller numbers and grain yield, indicating its potential utilization for yield improvement. Furthermore, the truncated OsCDC48–PSD128 protein lacking the C-terminal 27 amino acid residues showed a decreased level of ATPase activity. Removal of the C-terminus of OsCDC48 caused altered expression of cell cycle-related genes, changed the percentage of cells in G1 and G2/M phases, and abolished the interaction between OsCDC48 itself and between OsCDC48 and OsCDC48E, respectively. OsCDC48E knockout plants exhibited similar behavior to psd128 with premature senescence and plant death. Here, we showed that OsCDC48 (Os03g0151800) interacted with OsCDC48E (Os10g0442600), a homologue of OsCDC48, to control plant survival in rice. We previously isolated a rice CDC48 mutant (psd128) displaying premature senescence and death phenotype. We demonstrate that the C-terminus of OsCDC48 is essential for maintaining its full ATPase activity and OsCDC48/48E interaction is required to modulate cellular processes and plant survival in rice.Ĭell division cycle 48 (CDC48) belongs to the superfamily protein of ATPases associated with diverse cellular activities (AAA). General Significance: Identification of emerging functions of CDC48 in plants, opens new roads of research in immunity and provides new insights into the mechanisms of protein quality control. Furthermore, its involvement in plant immunity has recently emerged and first interacting partners have been identified, shedding light on its putative cellular activities. Major Conclusions: Evidence accumulated underline that CDC48 plays a crucial role in development, cell cycle regulation and protein turnover in plants. In the present review we intended to present the state of the art of the structure, regulation and functions of CDC48 in plants.
Scope of review: p97 is also conserved in plants (CDC48) but its functions are less understood.
P97 has been broadly studied in mammals (VCP/p97) and yeasts (CDC48: Cell Division Cycle 48/p97) and numerous investigations highlighted that this protein is post-translationally regulated, is structured in homohexamer and interacts with partners and cofactors that direct it to distinct cellular signalization pathway including protein quality control and degradation, cell cycle regulation, genome stability, vesicular trafficking, autophagy and immunity. Background: The chaperone-like p97 is a member of the AAA+ ATPase enzyme family that contributes to numerous cellular activities.