scholarly journals Gain-of-function mutations amplify cytotoxic FAM111 protease activity in human genetic disorders

2020 ◽  
Author(s):  
Saskia Hoffmann ◽  
Satyakrishna Pentakota ◽  
Andreas Mund ◽  
Peter Haahr ◽  
Fabian Coscia ◽  
...  
Keyword(s):  
Serine Protease ◽  
Proteolytic Activity ◽  
Protease Activity ◽  
Genetic Disorders ◽  
Point Mutations ◽  
Bone Dysplasia ◽  
Missense Mutations ◽  
Gain Of Function ◽  
Function Mechanism ◽  
Human Genetic Disorders

AbstractDominant missense mutations in the human serine protease FAM111A underlie perinatally lethal gracile bone dysplasia and Kenny-Caffey syndrome 1–3, yet how FAM111A mutations lead to disease is not known. We show that FAM111A proteolytic activity suppresses DNA replication and transcription by displacing key effectors of these processes from chromatin, triggering rapid programmed cell death by Caspase-dependent apoptosis to potently undermine cell viability. Patient-associated point mutations in FAM111A exacerbate these phenotypes by hyperactivating its intrinsic protease activity. Moreover, FAM111A forms a complex with the uncharacterized homologous serine protease FAM111B, point mutations in which cause a hereditary fibrosing poikiloderma syndrome 4, and we demonstrate that disease-associated FAM111B mutants display amplified proteolytic activity and phenocopy the cellular impact of deregulated FAM111A catalytic activity. Thus, patient-associated FAM111A and FAM111B mutations may drive multisystem disorders via a common gain-of-function mechanism that relieves inhibitory constraints on their protease activities to powerfully undermine cellular fitness.

scholarly journals SOST and DKK: Antagonists of LRP Family Signaling as Targets for Treating Bone Disease

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
James J. Mason ◽  
Bart O. Williams
Keyword(s):  
Bone Mass ◽  
Genetic Disorders ◽  
Low Density Lipoprotein ◽  
Point Mutations ◽  
Density Lipoprotein ◽  
Bone Diseases ◽  
The Body ◽  
High Bone Mass ◽  
High Bone ◽  
Human Genetic Disorders

The study of rare human genetic disorders has often led to some of the most significant advances in biomedical research. One such example was the body of work that resulted in the identification of the Low Density Lipoprotein-Related Protein (LRP5) as a key regulator of bone mass. Point mutations were identified that encoded forms of LRP5 associated with very high bone mass (HBM). HBM patients live to a normal age and do not appear to have increased susceptibility to carcinogenesis or other disease. Thus, devising methods to mimic the molecular consequences of this mutation to treat bone diseases associated with low bone mass is a promising avenue to pursue. Two groups of agents related to putative LRP5/6 functions are under development. One group, the focus of this paper, is based on antagonizing the functions of putative inhibitors of Wnt signaling, Dickkopf-1 (DKK1), and Sclerostin (SOST). Another group of reagents under development is based on the observation that LRP5 may function to control bone mass by regulating the secretion of serotonin from the enterrochromaffin cells of the duodenum.

scholarly journals Oligomerization of Mutant p53 R273H is not Required for Gain-of-Function Chromatin Associated Activities

2021 ◽  
Vol 9 ◽  
Author(s):  
George K. Annor ◽  
Nour Elshabassy ◽  
Devon Lundine ◽  
Don-Gerard Conde ◽  
Gu Xiao ◽  
...  
Keyword(s):  
Point Mutations ◽  
Site Directed Mutagenesis ◽  
Strong Interactions ◽  
Mutant P53 ◽  
Missense Mutations ◽  
Gain Of Function ◽  
Kinase Gene ◽  
Li Fraumeni Syndrome ◽  
Inherited Cancer ◽  
Associated Proteins

The TP53 gene is often mutated in cancer, with missense mutations found in the central DNA binding domain, and less often in the C-terminal oligomerization domain (OD). These types of mutations are found in patients with the rare inherited cancer predisposition disorder called Li-Fraumeni syndrome. We previously found that mutant p53 (mtp53) R273H associates with replicating DNA and promotes the chromatin association of replication-associated proteins mini-chromosome maintenance 2 (MCM2), and poly ADP-ribose polymerase 1(PARP1). Herein, we created dual mutants in order to test if the oligomerization state of mtp53 R273H played a role in chromatin binding oncogenic gain-of-function (GOF) activities. We used site-directed mutagenesis to introduce point mutations in the OD in wild-type p53 (wtp53), and mtp53 R273H expressing plasmids. The glutaraldehyde crosslinking assay revealed that both wtp53 and mtp53 R273H formed predominantly tetramers, while the single OD mutant A347D, and the dual mtp53 R273H-A347D, formed predominantly dimers. The R337C, L344P, mtp53 R273H-R337C, and mtp53 R273H-L344P proteins formed predominantly monomers. Wtp53 was able to activate the cyclin-dependent kinase gene p21/waf and the p53 feedback regulator MDM2. As expected, the transactivation activity was lost for all the single mutants, as well as the mtp53 R273H-dual mutants. Importantly, mtp53 R273H and the dual oligomerization mutants, R273H-A347D, R273H-R337C, and R273H-L344P were able to interact with chromatin. Additionally, the dual oligomerization mutants, R273H-A347D, R273H-R337C, and R273H-L344P, maintained strong interactions with MCM2 and PARP1. Our findings suggest that while mtp53 R273H can form tetramers, tetramer formation is not required for the GOF associated chromatin interactions.

scholarly journals Subtypes of the Plasmid-Encoded Serine Protease EspP in Shiga Toxin-Producing Escherichia coli: Distribution, Secretion, and Proteolytic Activity

2007 ◽  
Vol 73 (20) ◽  
pp. 6351-6359 ◽  
Author(s):  
Jens Brockmeyer ◽  
Martina Bielaszewska ◽  
Angelika Fruth ◽  
Marie Luise Bonn ◽  
Alexander Mellmann ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Serine Protease ◽  
Proteolytic Activity ◽  
Shiga Toxin ◽  
Point Mutations ◽  
Coagulation Factor ◽  
Factor V ◽  
Human Pathogens ◽  
E Coli ◽  
Bona Fide

ABSTRACT We investigated the prevalence, distribution, and structure of espP in Shiga toxin-producing Escherichia coli (STEC) and assessed the secretion and proteolytic activity of the encoded autotransporter protein EspP (extracellular serine protease, plasmid encoded). espP was identified in 56 of 107 different STEC serotypes. Sequencing of a 3,747-bp region of the 3,900-bp espP gene distinguished four alleles (espPα, espPβ, espPγ, and espPδ), with 99.9%, 99.2%, 95.3%, and 95.1% homology, respectively, to espP of E. coli O157:H7 strain EDL933. The espPβ, espPγ, and espPδ genes contained unique insertions and/or clustered point mutations that enabled allele-specific PCRs; these demonstrated the presence of espPα, espPβ, espPγ, and espPδ in STEC isolates belonging to 17, 16, 15, and 8 serotypes, respectively. Among four subtypes of EspP encoded by these alleles, EspPα (produced by enterohemorrhagic E. coli [EHEC] O157:H7 and the major non-O157 EHEC serotypes) and EspPγ cleaved pepsin A, human coagulation factor V, and an oligopeptide alanine-alanine-proline-leucine-para-nitroaniline, whereas EspPβ and EspPδ either were not secreted or were proteolytically inactive. The lack of proteolysis correlated with point mutations near the active serine protease site. We conclude that espP is widely distributed among STEC strains and displays genetic heterogeneity, which can be used for subtyping and which affects EspP activity. The presence of proteolytically active EspP in EHEC serogroups O157, O26, O111, and O145, which are bona fide human pathogens, suggests that EspP might play a role as an EHEC virulence factor.

scholarly journals Serine proteases in the extracellular preparations of Phytophthora infestans: does their presence relate to the aggressiveness of the pathogen?

2002 ◽  
Vol 38 (SI 1 - 6th Conf EFPP 2002) ◽  
pp. S102-S103
Author(s):  
J. Hamill ◽  
C. Selby ◽  
L.R. Cooke
Keyword(s):  
Phytophthora Infestans ◽  
Serine Protease ◽  
Ethyl Ester ◽  
Proteolytic Activity ◽  
Protease Activity ◽  
Serine Proteases ◽  
Daily Basis ◽  
Serine Protease Activity ◽  
Zoospore Suspension

In this study the aggressiveness of nine isolates of P. infestans was determined using detached leaflets from cultivars Bintje and Stirling. The growth of the isolates on the leaflets was recorded on a daily basis, for seven days, and an assessment of their aggressiveness could then be made. Extracellular preparations (ECPs) from the zoospore suspension of each isolate were used as a source of proteolytic activity. The ECPs were found to contain a level of serine protease activity using BTEE (N-Benzoyl-L-Tyrosine Ethyl Ester) as a substrate and recording the absorbance at 256 nm. The possible relationship between the serine protease activity and the aggressiveness of the isolate is discussed.

Mutational spectrum and deep intronic variants in the factor VIII gene of haemophilia A patients

2016 ◽  
Vol 36 (S 02) ◽  
pp. S25-S28 ◽  
Author(s):  
J. Oldenburg ◽  
C. R. Müller ◽  
S. Rost ◽  
J. E. Bach
Keyword(s):  
Factor Viii ◽  
Genomic Sequence ◽  
Genetic Disorders ◽  
Point Mutations ◽  
Diagnostic Methods ◽  
Haemophilia A ◽  
Missense Mutations ◽  
Factor Viii Gene ◽  
Current Standard ◽  
Intronic Variants

SummaryHaemophilia A (HA) is caused by a broad spectrum of different mutation types in the factor VIII gene (F8). In our patient cohort of more than 2600 HA patients as well as in other published studies, the most frequent cause are missense mutations in different F8 exons or the recurrent intron 22 inversion. Some exons and several specific nucleotide positions represent hot spots for point mutations in the examined cohort. About 4 % of cases remain without mutation after routine HA diagnostic methods including inversion PCRs, Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA). Deep intronic mutations cannot be detected by current standard HA diagnostics but have been reported for several genetic disorders. However, next generation sequencing (NGS) of the whole genomic sequence of the F8 gene allows to identify deep intronic variants. Conclusion: In general, NGS provides an effective approach to screen for different HA causing mutation types in the F8 gene.

A Novel Mutation Glyl672→Arg in Type 2A and a Homozygous Mutation in Type 2B von Willebrand Disease

1996 ◽  
Vol 76 (02) ◽  
pp. 253-257 ◽  
Author(s):  
Takeshi Hagiwara ◽  
Hiroshi Inaba ◽  
Shinichi Yoshida ◽  
Keiko Nagaizumi ◽  
Morio Arai ◽  
...  
Keyword(s):  
Missense Mutation ◽  
Novel Mutation ◽  
Point Mutations ◽  
Japanese Patients ◽  
Von Willebrand Disease ◽  
Homozygous Mutation ◽  
Missense Mutations ◽  
Reaction Products ◽  
Type 3 ◽  
Von Willebrand

SummaryGenetic materials from 16 unrelated Japanese patients with von Willebrand disease (vWD) were analyzed for mutations. Exon 28 of the von Willebrand factor (vWF) gene, where point mutations have been found most frequent, was screened by various restriction-enzyme analyses. Six patients were observed to have abnormal restriction patterns. By sequence analyses of the polymerase chain-reaction products, we identified a homozygous R1308C missense mutation in a patient with type 2B vWD; R1597W, R1597Q, G1609R and G1672R missense mutations in five patients with type 2A; and a G1659ter nonsense mutation in a patient with type 3 vWD. The G1672R was a novel missense mutation of the carboxyl-terminal end of the A2 domain. In addition, we detected an A/C polymorphism at nucleotide 4915 with HaeIII. There was no particular linkage disequilibrium of the A/C polymorphism, either with the G/A polymorphism at nucleotide 4391 detected with Hphl or with the C/T at 4891 detected with BstEll.

scholarly journals Effect of Plant Growth Regulators on Protease Activity in Forest Floor of Norway Spruce Stand

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 665
Author(s):  
Ladislav Holik ◽  
Jiří Volánek ◽  
Valerie Vranová
Keyword(s):  
Organic Matter ◽  
Proteolytic Activity ◽  
Protease Activity ◽  
Forest Floor ◽  
Soil Microbial Activity ◽  
Inhibitory Effects ◽  
Chlorocholine Chloride ◽  
Soil Microbial ◽  
Native Soil ◽  
Transformation Processes

Soil proteases are involved in organic matter transformation processes and, thus, influence ecosystem nutrient turnovers. Phytohormones, similarly to proteases, are synthesized and secreted into soil by fungi and microorganisms, and regulate plant rhizosphere activity. The aim of this study was to determine the effect of auxins, cytokinins, ethephon, and chlorocholine chloride on spruce forest floor protease activity. It was concluded that the presence of auxins stimulated native proteolytic activity, specifically synthetic auxin 2-naphthoxyacetic acid (16% increase at added quantity of 5 μg) and naturally occurring indole-3-acetic acid (18%, 5 μg). On the contrary, cytokinins, ethephon and chlorocholine chloride inhibited native soil protease activity, where ethephon (36% decrease at 50 μg) and chlorocholine chloride (34%, 100 μg) showed the highest inhibitory effects. It was concluded that negative phytohormonal effects on native proteolytic activity may slow down organic matter decomposition rates and hence complicate plant nutrition. The study enhances the understanding of rhizosphere exudate effects on soil microbial activity and soil nitrogen cycle.

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