UFMylation involves the covalent modification of substrate proteins with UFM1 (Ubiquitin-fold modifier 1) and is important for maintaining ER homeostasis. Stalled translation triggers the UFMylation of ER-bound ribosomes and activates C53-mediated autophagy to clear toxic polypeptides. C53 contains noncanonical shuffled ATG8-interacting motifs (sAIMs) that are essential for ATG8 interaction and autophagy initiation. However, the mechanistic basis of sAIM-mediated ATG8 interaction remains unknown. Here, we show that C53 and sAIMs are conserved across eukaryotes but secondarily lost in fungi and various algal lineages. Biochemical assays showed that the unicellular alga Chlamydomonas reinhardtii has a functional UFMylation pathway, refuting the assumption that UFMylation is linked to multicellularity. Comparative structural analyses revealed that both UFM1 and ATG8 bind sAIMs in C53, but in a distinct way. Conversion of sAIMs into canonical AIMs impaired binding of C53 to UFM1, while strengthening ATG8 binding. Increased ATG8 binding led to the autoactivation of the C53 pathway and sensitization of Arabidopsis thaliana to ER stress. Altogether, our findings reveal an ancestral role of sAIMs in UFMylation-dependent fine-tuning of C53-mediated autophagy activation.

Roots are highly plastic organs enabling plants to adapt to a changing below-ground environment. In addition to abiotic factors like nutrients or mechanical resistance, plant roots also respond to temperature variation. Below the heat stress threshold, Arabidopsis thaliana seedlings react to elevated temperature by promoting primary root growth, possibly to reach deeper soil regions with potentially better water saturation. While above-ground thermomorphogenesis is enabled by thermo-sensitive cell elongation, it was unknown how temperature modulates root growth. We here show that roots are able to sense and respond to elevated temperature independently of shoot-derived signals. This response is mediated by a yet unknown root thermosensor that employs auxin as a messenger to relay temperature signals to the cell cycle. Growth promotion is achieved primarily by increasing cell division rates in the root apical meristem, depending on de novo local auxin biosynthesis and temperature-sensitive organization of the polar auxin transport system. Hence, the primary cellular target of elevated ambient temperature differs fundamentally between root and shoot tissues, while the messenger auxin remains the same.

The cullin‐RING E3 ligases (CRLs) regulate diverse cellular processes in all eukaryotes. CRL activity is controlled by several proteins or protein complexes, including NEDD8, CAND1, and the CSN. Recently, a mammalian protein called Glomulin (GLMN) was shown to inhibit CRLs by binding to the RING BOX (RBX1) subunit and preventing binding to the ubiquitin‐conjugating enzyme. Here, we show that Arabidopsis ABERRANT LATERAL ROOT FORMATION4 (ALF4) is an ortholog of GLMN. The alf4 mutant exhibits a phenotype that suggests defects in plant hormone response. We show that ALF4 binds to RBX1 and inhibits the activity of SCFTIR1, an E3 ligase responsible for degradation of the Aux/IAA transcriptional repressors. In vivo, the alf4 mutation destabilizes the CUL1 subunit of the SCF. Reduced CUL1 levels are associated with increased levels of the Aux/IAA proteins as well as the DELLA repressors, substrate of SCFSLY1. We propose that the alf4 phenotype is partly due to increased levels of the Aux/IAA and DELLA proteins.

The first total synthesis of cordyheptapeptide A is described. The synthesis is accomplished by a convergent approach featuring a combination of peptide coupling and the Ugi reaction for the preparation of the main building blocks and the acyclic precursor. The assembly of an N-methylated fragment by the Ugi reaction comprised the utilization of a convertible isonitrile followed by activation of the C-terminal amide. Two different macrocyclization sites were evaluated, proving greater efficacy the macrolactamization at the site Ile-Tyr, likely due of a more suitable conformational bias of the acyclic precursor having an internal β-turn centered at the N-Me-d-Phe-Pro moiety.

Organocatalytic nucleophilic addition of 2-hydroxylnaphthaquinone to imines is reported. This new route can be used to produce enantioenriched Mannich bases with excellent yields and moderate enantioselectivities.

Small libraries of peptoid-based macro(multi)cycles were produced by applying combinatorial principles to the MiB methodology. This combinatorial approach features the incorporation of varied building blocks into the resulting macrocycles by mixing all the components in the same reaction pot. Both skeletal and appendage diversity could be generated in one shot due to the multicomponent nature of the system. HPLC and ESI-MS analyses showed a well-distributed composition of the libraries and revealed the presence of all possible macrocycles resulting from the different combinations of building blocks, especially of members with differentially substituted bridges not available by any other one-pot ­approach.

N-Tritylaziridino alcohols have been easily synthesized in a straightforward synthetic route from an inexpensive and easily available chiral pool. They were used in the enantioselective alkenylzinc additions to aldehydes furnishing the products in excellent yields and stereoselectivities up to 97%.

The scope of chromium(II)-mediated Takai-Utimoto ­reactions was extended to previously unconvertable secondary alkylhalides. Optimization allowed yields of up to over 95%.

The application of 2-(2,2-dimethoxyethyl) phenyl iso­nitrile in Ugi, Passerini, and Ugi-Smiles reactions is described. The simple transformation to highly activated indolyl amides allows functional-group conversion of the isonitrile moiety into a variety of carboxylic acid derivatives, overall acting as a neutral, nucleophilic COOH equivalent.

For the first time, homo-Mannich reactions with unmasked homoenolates have been achieved by adding homoenolate precursor 1 and imines 5. The key to this reaction is the right choice of the Lewis acids - Cu(OTf)2 proved to be most suitable for preparing the homoenolate and activation of the imine. An asymmetric catalytic version of this reaction is provided by using chiral, non-­racemic phenyl-derived bisoxazolidine as ligand for the Lewis acid.