MicroProteins:Dynamic and accurate regulation of protein activity

Proteins usually assemble oligomers or high-order complexes to increase their efficiency and specificity in biological processes.The dynamic equilibrium of complex formation and disruption imposes reversible regulation of protein function.MicroProteins are small,single-domain proteins that directly bind target protein complexes and disrupt their assembly.Growing evidence shows that microProteins are efficient regulators of protein activity at the post-translational level.In the last few decades,thousands of plant microProteins have been predicted by computational approaches,but only a few have been experimentally validated.Recent studies highlighted the mechanistic working modes of newly-identified microProteins in Arabidopsis and other plant species.Here,we review characterized microProteins,including their biological roles,regulatory targets,and modes of action.In particular,we focus on microProtein-directed allosteric modulation of key components in light signaling pathways,and we summarize the biogenesis and evolutionary trajectory of known microProteins in plants.Understanding the regulatory mechanisms of microProteins is an important step towards potential utilization of microProteins as versatile biotechnological tools in crop bioengineering.

Clinical characteristics of patients with early-and late-onset optic neuromyelitis optica spectrum disease

Objective:To analyze the different clinical features of patients with early-onset(EO-NMOSDs)and late-onset neuromyelitis optica spectrum diseases(LO-NMOSDs).Methods:A total of 51patients with neuromyelitis optica spectrum disease who were diagnosed in our hospital for the first time from January 2015 to December 2022 were included in the First Affiliated Hospital of Hainan Medical College and divided into 22 cases in the EO-NMOSDs group and 29 cases in the LO-NMOSDs group according to whether the age of onset was 50 years old.The basic data,Extended Disability Status Scale(EDSS)score,blood and cerebrospinal fluid test indicators of the two groups were statistically analyzed.Results:There were no significant differences in demographic characteristics,clinical features and serum AQP-4 antibody positivity rate between the two groups(all P>0.05),and there were significant differences in triglycerides(TG),low-density lipoprotein(LDL),apolipoprotein A(APOA),apolipoprotein B(APOB)and lipoprotein a(P=0.010,P=0.048,P=0.014,P=0.061,P=0.001,respectively),and cerebrospinal fluid LDH,There were significant differences between microprotein quantification and EDSS score(P=0.018,P=0.034,P=0.025,respectively),and the level of microprotein quantification in cerebrospinal fluid of LO-NMOSDs had a certain correlation with the degree of disability(r=0.52,P<0.03).Conclusion:LO-NMOSDs and EO-NMOSDs group patients have similar demographic characteristics,serum AQP-4 antibody positive rate and clinical features,but compared with EO-NMOSDs,patients in LO-NMOSDs group are prone to abnormal lipid metabolism,higher trace proteins in cerebrospinal fluid and more likely to be disabled,and among LO-NMOSDs,the higher the trace protein in the cerebrospinal fluid,the more severe the disability status of patients.

Broad-spectrum ginsentides are principal bioactives in unraveling the cure-all effects of ginseng

Stress and illness connection is complex and involves multiple physiological systems.Panax ginsengs,reputed for their broad-spectrum“cure-all”effect,are widely prescribed to treat stress and related illnesses.However,the identity of ginseng’s“cure-all”medicinal compounds that relieve stress remains unresolved.Here,we identify ginsentides as the principal bioactives that coordinate multiple systems to restore homeostasis in response to stress.Ginsentides are disulfide-rich,cell-penetrating and proteolytic-stable microproteins.Using affinity-enrichment mass spectrometry target identification together with in vitro,ex vivo and in vivo validations,we show that highly purified or synthetic ginsentides promote vasorelaxation by producing nitric oxide through endothelial cells via intracellular PI3K/Akt signaling pathway,alleviate a1-adrenergic receptor overactivity by reversing phenylephrine-induced constriction of aorta,decrease monocyte adhesion to endothelial cells via CD166/ESAM/CD40 and inhibit P2Y12 receptors to reduce platelet aggregation.Orally administered ginsentides were effective in animal models to reduce ADP-induced platelet aggregation,to prevent collagen and adrenalineinduced pulmonary thrombosis as well as anti-stress behavior of tail suspension and forced swimming tests in mice.Together,these results strongly suggest that ginsentides are the principal panacea compounds of ginsengs because of their ability to target multiple extra-and intra-cellular proteins to reverse stress-induced damages.

Ribosome profiling analysis identified a KRAS-interacting microprotein that represses oncogenic signaling in hepatocellular carcinoma cells

The roles of concealed microproteins encoded by long noncoding RNAs(lncRNAs)are gradually being exposed,but their functions in tumorigenesis are still largely unclear.Here,we identify and characterize a conserved 99-amino acid microprotein named KRASIM that is encoded by the putative lncRNA NCBP2-AS2.KRASIM is differentially expressed in normal hepatocytes and hepatocellular carcinoma(HCC)cells and can suppress HCC cell growth and proliferation.Mechanistically,KRASIM interacts and colocalizes with the KRAS protein in the cytoplasm of human HuH-7 hepatoma cells.More importantly,the overexpression of KRASIM decreases the KRAS protein level,leading to the inhibition of ERK signaling activity in HCC cells.These results demonstrate a novel microprotein repressor of the KRAS pathway for the first time and provide new insights into the regulatory mechanisms of oncogenic signaling and HCC therapy.

Controlling flowering of Medicago sativa(alfalfa)by inducing dominant mutations

Breeding plants with polyploid genomes is challenging because functional redundancy hampers the identification of loss-of-function mutants.Medicago sativa is tetraploid and obligate outcrossing,which together with inbreeding depression complicates traditional breeding approaches in obtaining plants with a stable growth habit.Inducing dominant mutations would provide an alternative strategy to introduce domestication traits in plants with high gene redundancy.Here we describe two complementary strategies to induce dominant mutations in the M.sativa genome and how they can be relevant in the control of flowering time.First,we outline a genome-engineering strategy that harnesses the use of microProteins as developmental regulators.MicroProteins are small proteins that appeared during genome evolution from genes encoding larger proteins.Genomeengineering allows us to retrace evolution and create microProtein-coding genes de novo.Second,we provide an inventory of genes regulated by microRNAs that control plant development.Making respective gene transcripts microRNA-resistant by inducing point mutations can uncouple microRNA regulation.Finally,we investigated the recently published genomes of M.sativa and provide an inventory of breeding targets,some of which,when mutated,are likely to result in dominant traits.