Biology subjects

Maio, F.

Publications and source records attributed to Maio, F..

3 recordsLinked to original sources

bioRxiv2024

A SUMO interacting motif in the Replication initiator protein of Tomato yellow leaf curl virus is required for viral replication

CRESS-DNA viruses form a diverse group of viruses that use rolling-circle replication to replicate their genomes. They infect organisms in almost all branches of the eukaryotic tree of life. All CRESS-DNA viruses have one protein in common, the Replication initiator protein (Rep), which orchestrates viral replication using the host DNA replication machinery. In the case of the plant-infecting Geminiviridae, this multifunctional protein both recruits the host DNA replication machinery and manipulates posttranslational modification including Small ubiquitin-like modifier (SUMO) conjugation. In fact, Rep from two different geminiviruses, Tomato yellow leaf curl virus (TYLCV) and Tomato golden mosaic virus (TGMV), was shown to interact with the SUMO conjugating enzyme SCE1. Here, we demonstrate that also TYLCV Rep interacts with Arabidopsis SUMO1 and report on a SUMO interacting motif (SIM) in the SF3 helicase domain of Rep. Remarkably, an intact SIM proved to be important for the interaction of Rep with both SUMO1 and SCE1. The same motif was also essential for viral replication and Rep ATPase activity. Our findings thus connect the interaction between Rep and the SUMO machinery with viral replication of TYLCV. ImportanceThe identification of a non-canonical SUMO-interacting motif (SIM) within the Rep protein of Tomato yellow leaf curl virus (TYLCV) reveals a connection between viral replication and a protein modification, SUMOylation. Importantly, the motif was found to be conserved between Rep proteins from different geminiviruses. Functionally, the motif was critical for the interaction of Rep with proteins of the SUMO machinery, viral DNA replication, and Rep ATPase acitvity. In particular, the third position of the motif was important for each of these activities. We thus uncover a novel mechanism on how geminiviruses recruit the SUMO machinery likely to their own need.

plant biology↗

bioRxiv2018

The SUMO conjugation complex self-assembles into nuclear bodies independent of SIZ1 and COP1

One sentence SummarySUMO conjugation activity causes formation of SUMO nuclear bodies, which strongly overlap with COP1 bodies thanks to a substrate-binding (VP) motif in the E3 ligase SIZ1 that acts as bridge protein.\n\nAbstractAttachment of the small ubiquitin-like modifier SUMO to substrate proteins modulates their turnover, activity or interaction partners. An unresolved question is how this SUMO conjugation activity concentrates the enzymes involved and the substrates into uncharacterized nuclear bodies (NBs). We here define the requirements for the formation of SUMO NBs and for their subsequent co-localisation with the master regulator of growth, the E3 ubiquitin ligase COP1. COP1 activity results in degradation of transcription factors, which primes the transcriptional response that underlies elongation growth induced by night-time and high ambient temperatures (skoto- and thermomorphogenesis, respectively). SUMO conjugation activity itself is sufficient to target the SUMO machinery into NBs. Co-localization of these bodies with COP1 requires besides SUMO conjugation activity, a SUMO acceptor site in COP1 and the SUMO E3 ligase SIZ1. We find that SIZ1 docks in the substrate-binding pocket of COP1 via two VP motifs - a known peptide motif of COP1 substrates. The data reveal that SIZ1 physically connects COP1 and SUMO conjugation activity in the same NBs that can also contain the blue-light receptors CRY1 and CRY2. Our findings thus suggest that sumoylation apparently coordinates COP1 activity inside these NBs; a mechanism that potentially explains how SIZ1 and SUMO both control the timing and amplitude of the high-temperature growth response. The strong co-localization of COP1 and SUMO in these NBs might also explain why many COP1 substrates are sumoylated.\n\nFunding informationThe Netherlands Scientific Organisation (ALW-VIDI grant 864.10.004 to HvdB) and the Topsector T&U program Better Plants for Demands (grant 1409-036 to HvdB), including the partnering breeding companies, supported this work; FM is financially supported by Keygene N.V. (The Netherlands).

plant biology↗

bioRxiv2018

Geminivirus Replication Protein impairs SUMO conjugation of PCNA at two acceptor sites

Geminiviruses are DNA viruses that replicate in nuclei of infected plant cells using the plant DNA replication machinery, including PCNA (Proliferating cellular nuclear antigen), a cofactor that orchestrates genome duplication and maintenance by recruiting crucial players to replication forks. These viruses encode a multifunctional protein, Rep, which is essential for viral replication, induces the accumulation of the host replication machinery and interacts with several host proteins, including PCNA and the SUMO E2 conjugation enzyme (SCE1). Post-translational modification of PCNA by ubiquitin or SUMO plays an essential role in the switching of PCNA between interacting partners during DNA metabolism processes (e.g. replication, recombination, repair, etc.). In yeast, PCNA sumoylation has been associated to DNA repair involving homologous recombination (HR). Previously, we reported that ectopic Rep expression results in very specific changes in the sumoylation pattern of plant cells. In this work, we show, using a reconstituted sumoylation system in Escherichia coli, that tomato PCNA is sumoylated at two residues, K254 and K164, and that co-expression of the geminivirus protein Rep suppresses sumoylation at these lysines. Finally, we confirm that PCNA is sumoylated in planta and that Rep also interferes with PCNA sumoylation in plant cells.\n\nImportanceSUMO adducts have a key role in regulating the activity of animal and yeast PCNA on DNA repair and replication. Our work demonstrates for the first time that sumoylation of plant PCNA occurs in plant cells and that a plant virus interferes with this modification. This work marks the importance of sumoylation in allowing viral infection and replication in plants. Moreover, it constitutes a prime example of viral proteins interfering with post-translational modifications of selected host factors to create a proper environment for infection.

plant biology↗