TY - JOUR A1 - John, Sheeba A1 - Olas, Justyna Jadwiga A1 - Müller-Röber, Bernd T1 - Regulation of alternative splicing in response to temperature variation in plants JF - Journal of experimental botany N2 - Plants have evolved numerous molecular strategies to cope with perturbations in environmental temperature, and to adjust growth and physiology to limit the negative effects of extreme temperature. One of the strategies involves alternative splicing of primary transcripts to encode alternative protein products or transcript variants destined for degradation by nonsense-mediated decay. Here, we review how changes in environmental temperature-cold, heat, and moderate alterations in temperature-affect alternative splicing in plants, including crops. We present examples of the mode of action of various temperature-induced splice variants and discuss how these alternative splicing events enable favourable plant responses to altered temperatures. Finally, we point out unanswered questions that should be addressed to fully utilize the endogenous mechanisms in plants to adjust their growth to environmental temperature. We also indicate how this knowledge might be used to enhance crop productivity in the future. KW - alternative splicing KW - ambient temperature KW - cold KW - heat KW - plants KW - stress KW - adaptation Y1 - 2021 U6 - https://doi.org/10.1093/jxb/erab232 SN - 0022-0957 SN - 1460-2431 VL - 72 IS - 18 SP - 6150 EP - 6163 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Hasnat, Muhammad Abrar A1 - Zupok, Arkadiusz A1 - Olas-Apelt, Justyna Jadwiga A1 - Müller-Röber, Bernd A1 - Leimkühler, Silke T1 - A-type carrier proteins are involved in [4Fe-4S] cluster insertion into the radical S-adenosylmethionine protein MoaA for the synthesis of active molybdoenzymes JF - Journal of bacteriology N2 - Iron sulfur (Fe-S) clusters are important biological cofactors present in proteins with crucial biological functions, from photosynthesis to DNA repair, gene expression, and bioenergetic processes. For the insertion of Fe-S clusters into proteins, A-type carrier proteins have been identified. So far, three of them have been characterized in detail in Escherichia coli, namely, IscA, SufA, and ErpA, which were shown to partially replace each other in their roles in [4Fe-4S] cluster insertion into specific target proteins. To further expand the knowledge of [4Fe-4S] cluster insertion into proteins, we analyzed the complex Fe-S cluster-dependent network for the synthesis of the molybdenum cofactor (Moco) and the expression of genes encoding nitrate reductase in E. coli. Our studies include the identification of the A-type carrier proteins ErpA and IscA, involved in [4Fe-4S] cluster insertion into the radical Sadenosyl-methionine (SAM) enzyme MoaA. We show that ErpA and IscA can partially replace each other in their role to provide [4Fe-4S] clusters for MoaA. Since most genes expressing molybdoenzymes are regulated by the transcriptional regulator for fumarate and nitrate reduction (FNR) under anaerobic conditions, we also identified the proteins that are crucial to obtain an active FNR under conditions of nitrate respiration. We show that ErpA is essential for the FNR-dependent expression of the narGHJI operon, a role that cannot be compensated by IscA under the growth conditions tested. SufA does not appear to have a role in Fe-S cluster insertion into MoaA or FNR under anaerobic growth employing nitrate respiration, based on the low level of gene expression.
IMPORTANCE Understanding the assembly of iron-sulfur (Fe-S) proteins is relevant to many fields, including nitrogen fixation, photosynthesis, bioenergetics, and gene regulation. Remaining critical gaps in our knowledge include how Fe-S clusters are transferred to their target proteins and how the specificity in this process is achieved, since different forms of Fe-S clusters need to be delivered to structurally highly diverse target proteins. Numerous Fe-S carrier proteins have been identified in prokaryotes like Escherichia coli, including ErpA, IscA, SufA, and NfuA. In addition, the diverse Fe-S cluster delivery proteins and their target proteins underlie a complex regulatory network of expression, to ensure that both proteins are synthesized under particular growth conditions. KW - iron-sulfur clusters KW - Moco biosynthesis KW - MoaA KW - A-type carrier protein KW - FNR KW - nitrate reductase KW - molybdenum cofactor Y1 - 2021 U6 - https://doi.org/10.1128/JB.00086-21 SN - 1098-5530 VL - 203 IS - 12 PB - American Society for Microbiology CY - Washington ER -