82 research outputs found
NAC transcription factors in senescence:from molecular structure to function in crops
Within the last decade, NAC transcription factors have been shown to play essential roles in senescence, which is the focus of this review. Transcriptome analyses associate approximately one third of Arabidopsis NAC genes and many crop NAC genes with senescence, thereby implicating NAC genes as important regulators of the senescence process. The consensus DNA binding site of the NAC domain is used to predict NAC target genes, and protein interaction sites can be predicted for the intrinsically disordered transcription regulatory domains of NAC proteins. The molecular characteristics of these domains determine the interactions in gene regulatory networks. Emerging local NAC-centered gene regulatory networks reveal complex molecular mechanisms of stress- and hormone-regulated senescence and basic physiological steps of the senescence process. For example, through molecular interactions involving the hormone abscisic acid, Arabidopsis NAP promotes chlorophyll degradation, a hallmark of senescence. Furthermore, studies of the functional rice ortholog, OsNAP, suggest that NAC genes can be targeted to obtain specific changes in lifespan control and nutrient remobilization in crop plants. This is also exemplified by the wheat NAM1 genes which promote senescence and increase grain zinc, iron, and protein content. Thus, NAC genes are promising targets for fine-tuning senescence for increased yield and quality
Fra forsøg til forankring: Flersproget faglig skrivning på bacheloruddannelsen i biokemi
I videregående uddannelse har det i lang tid været nødvendigt for studerende at kunne navigere mellem flere sprog, særligt dansk og engelsk. Dette stiller store krav til de studerende, men det udfordrer også deres undervisere, som ikke nødvendigvis oplever, at de har den tilstrækkelige viden eller ekspertise til at hjælpe de studerende med at udvikle faglige kommunikative kompetencer på flere sprog. I denne artikel diskuterer vi denne problemstilling i relation til et projektkursus på bacheloruddannelsen i biokemi på Københavns Universitet. Her har kursets undervisere og to sprogkonsulenter siden 2016 samarbejdet om et tiltag, som skal styrke de studerendes faglige skrivning på dansk og engelsk. I artiklen beskriver vi først selve projektkurset, hvorefter vi præsenterer indholdet på to skriveworkshops, der skal støtte de studerendes arbejde med et biokemisk essay, som de skal skrive på enten dansk eller engelsk. Vi præsenterer og forklarer konkrete øvelser og aktiviteter, som indgår i tiltaget, og som andre, der arbejder med skrivekompetencer på flere sprog, vil kunne inddrage i egne undervisningsforløb. Endelig diskuterer vi, med afsæt i evalueringer, styrker og svagheder ved tiltaget, herunder de problemstillinger og muligheder, der ligger i det tværfaglige samarbejde.
Fra forsøg til forankring: Flersproget faglig skrivning på bacheloruddannelsen i biokemi
I videregående uddannelse har det i lang tid været nødvendigt for studerende at kunne navigere mellem flere sprog, særligt dansk og engelsk. Dette stiller store krav til de studerende, men det udfordrer også deres undervisere, som ikke nødvendigvis oplever, at de har den tilstrækkelige viden eller ekspertise til at hjælpe de studerende med at udvikle faglige kommunikative kompetencer på flere sprog. I denne artikel diskuterer vi denne problemstilling i relation til et projektkursus på bacheloruddannelsen i biokemi på Københavns Universitet. Her har kursets undervisere og to sprogkonsulenter siden 2016 samarbejdet om et tiltag, som skal styrke de studerendes faglige skrivning på dansk og engelsk. I artiklen beskriver vi først selve projektkurset, hvorefter vi præsenterer indholdet på to skriveworkshops, der skal støtte de studerendes arbejde med et biokemisk essay, som de skal skrive på enten dansk eller engelsk. Vi præsenterer og forklarer konkrete øvelser og aktiviteter, som indgår i tiltaget, og som andre, der arbejder med skrivekompetencer på flere sprog, vil kunne inddrage i egne undervisningsforløb. Endelig diskuterer vi, med afsæt i evalueringer, styrker og svagheder ved tiltaget, herunder de problemstillinger og muligheder, der ligger i det tværfaglige samarbejde.
Evolutionary conservation of the intrinsic disorder-based Radical-Induced Cell Death1 hub interactome
Udfordringer ved undervisning i enzymer - Bidrag fra det virtuelle laboratorium
Enzymer er et centralt emne i biokemiundervisning. Det forudsætter og anvender grundlæggende viden inden for og kompetencer i kemi og matematik. Artiklen undersøger hvilke forståelsesvanskeligheder og udfordringer der er knyttet til dette område, såvel som virtuelle øvelsers potentiale i denne kontekst. Specifikt har vi afprøvet og deltaget i udviklingen af en virtuel øvelse i enzymkinetik. Labsters Virtuelle Laboratorium omfatter læringsmuligheder baseret på animationer, quizzer og simuleringer. Fokusgruppeinterviews med studerende på en række biokemikurser tyder på at virtuelle øvelser kan være relevante som supplement til teoretiske kurser eller som forberedelse til laboratorieøvelser. The topic of enzymes is a key topic in biochemistry teaching. It presupposes as well as applies a number of fundamental concepts in chemistry and mathematics. We investigate problems of conceptual understanding and the challenges that students meet in this domain, as well as the potential role of virtual exercises in this context. We have specifically tested and participated in the development of a virtual exercise in enzyme kinetics. The Virtual laboratory of Labster provides learning opportunities based on animations, quizzes, and simulations. Focus groups with students from a number of biochemistry courses indicate that virtual exercises can be relevant as a supplement to theoretical courses or as preparation for hands-on exercises
A DNA-binding-site landscape and regulatory network analysis for NAC transcription factors in Arabidopsis thaliana.
Target gene identification for transcription factors is a prerequisite for the systems wide understanding of organismal behaviour. NAM-ATAF1/2-CUC2 (NAC) transcription factors are amongst the largest transcription factor families in plants, yet limited data exist from unbiased approaches to resolve the DNA-binding preferences of individual members. Here, we present a TF-target gene identification workflow based on the integration of novel protein binding microarray data with gene expression and multi-species promoter sequence conservation to identify the DNA-binding specificities and the gene regulatory networks of 12 NAC transcription factors. Our data offer specific single-base resolution fingerprints for most TFs studied and indicate that NAC DNA-binding specificities might be predicted from their DNA-binding domain's sequence. The developed methodology, including the application of complementary functional genomics filters, makes it possible to translate, for each TF, protein binding microarray data into a set of high-quality target genes. With this approach, we confirm NAC target genes reported from independent in vivo analyses. We emphasize that candidate target gene sets together with the workflow associated with functional modules offer a strong resource to unravel the regulatory potential of NAC genes and that this workflow could be used to study other families of transcription factors
Heterologous expression and characterization of wild-type and mutant forms of a 26 kDa endochitinase from barley (Hordeum vulgare L.)
Disorder in a two-domain neuronal Ca2+-binding protein regulates domain stability and dynamics using ligand mimicry.
Funder: Lundbeckfonden; doi: http://dx.doi.org/10.13039/501100003554Funder: Villum Fonden (DK)Understanding the interplay between sequence, structure and function of proteins has been complicated in recent years by the discovery of intrinsically disordered proteins (IDPs), which perform biological functions in the absence of a well-defined three-dimensional fold. Disordered protein sequences account for roughly 30% of the human proteome and in many proteins, disordered and ordered domains coexist. However, few studies have assessed how either feature affects the properties of the other. In this study, we examine the role of a disordered tail in the overall properties of the two-domain, calcium-sensing protein neuronal calcium sensor 1 (NCS-1). We show that loss of just six of the 190 residues at the flexible C-terminus is sufficient to severely affect stability, dynamics, and folding behavior of both ordered domains. We identify specific hydrophobic contacts mediated by the disordered tail that may be responsible for stabilizing the distal N-terminal domain. Moreover, sequence analyses indicate the presence of an LSL-motif in the tail that acts as a mimic of native ligands critical to the observed order-disorder communication. Removing the disordered tail leads to a shorter life-time of the ligand-bound complex likely originating from the observed destabilization. This close relationship between order and disorder may have important implications for how investigations into mixed systems are designed and opens up a novel avenue of drug targeting exploiting this type of behavior
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