Cristian Carrasco-López, Pedro Carrasco, Julio Salinas, Rosa María Esquinas-Ariza, Miguel A. Blázquez, David Esteve-Bruna, Noel Blanco-Touriñán, Javier Forment, Claudio Novella-Rausell, Alberto Palacios-Abella, Francesca Resentini, Antonio Serrano-Mislata, David Alabadí, Ministerio de Economía y Competitividad (España), European Commission, Ministerio de Educación (España), Blanco-Touriñán, Noel, Esteve-Bruna, David, Serrano-Mislata, Antonio, Esquinas-Ariza, Rosa María, Resentini, Francesca, Forment, Javier, Carrasco-López, Cristian, Novella Rausell, Claudio, Palacios-Abella, Alberto, Carrasco, Pedro, Salinas, Julio, Blázquez, Miguel Ángel, Alabadí, David, Blanco-Touriñán, Noel [0000-0003-4610-6110], Esteve-Bruna, David [0000-0001-5143-0914], Serrano-Mislata, Antonio [0000-0002-8828-1809], Esquinas-Ariza, Rosa María [0000-0002-3354-7534], Resentini, Francesca [0000-0003-0033-6930], Forment, Javier [0000-0002-1872-4061], Carrasco-López, Cristian [0000-0002-7756-2218], Novella Rausell, Claudio [0000-0002-7383-6090], Palacios-Abella, Alberto [0000-0002-0086-4488 ], Carrasco, Pedro [0000-0001-7900-6146], Salinas, Julio [0000-0003-2020-0950], Blázquez, Miguel Ángel [0000-0001-5743-0448], and Alabadí, David [0000-0001-8492-6713]
17 p.-7 fig., The prefoldin complex (PFDc) was identified in humans as a co-chaperone of the cytosolic chaperonin T-COMPLEX PROTEIN RING COMPLEX (TRiC)/CHAPERONIN CONTAINING TCP-1 (CCT). PFDc is conserved in eukaryotes and is composed of subunits PFD1–6, and PFDc-TRiC/CCT folds actin and tubulins. PFDs also participate in a wide range of cellular processes, both in the cytoplasm and in the nucleus, and their malfunction causes developmental alterations and disease in animals and altered growth and environmental responses in yeast and plants. Genetic analyses in yeast indicate that not all of their functions require the canonical complex. The lack of systematic genetic analyses in plants and animals, however, makes it difficult to discern whether PFDs participate in a process as the canonical complex or in alternative configurations, which is necessary to understand their mode of action. To tackle this question, and on the premise that the canonical complex cannot be formed if one subunit is missing, we generated an Arabidopsis (Arabidopsis thaliana) mutant deficient in the six PFDs and compared various growth and environmental responses with those of the individual mutants. In this way, we demonstrate that the PFDc is required for seed germination, to delay flowering, or to respond to high salt stress or low temperature, whereas at least two PFDs redundantly attenuate the response to osmotic stress. A coexpression analysis of differentially expressed genes in the sextuple mutant identified several transcription factors, including ABA INSENSITIVE 5 (ABI5) and PHYTOCHROME-INTERACTING FACTOR 4, acting downstream of PFDs. Furthermore, the transcriptomic analysis allowed assigning additional roles for PFDs, for instance, in response to higher temperature., This work was supported by grants from the Spanish Ministry of Economy and Competitiveness and “Agencia Estatal de Investigación”/FEDER/European Union (BIO2013-43184-P to D.A. and M.A.B., and BIO2016-79133-P and PID2019-109925GB-I00 to D.A.). N.B.-T., A.S.-M., and A.P.-A.were recipient of Ministerio de Economía y Competitividad(BES-2014-068868), EU MSCA-IF (H2020-MSCA-IF-2016- 746396) and Ministerio de Educación (FPU17/05186) fellowships, respectively.