Anin silicoapproach to determine inter-subunit affinities in human septin complexes DOI Creative Commons
Benjamin Grupp, Justin A. Lemkul, Thomas Gronemeyer

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2022, Volume and Issue: unknown

Published: Dec. 20, 2022

Abstract The septins are a conserved family of filament-forming guanine nucleotide binding proteins, often named the fourth component cytoskeleton. Correctly assembled septin structures required for essential intracellular processes such as cytokinesis, vesicular transport, polarity establishment, and cellular adhesion. Structurally, belong to P-Loop NTPases but they do not mediate signals effectors through GTP hydrolysis. hydrolysis believed contribute complex integrity, biochemical approaches addressing this topic hampered by stability complexes after recombinant expression lack nucleotide-depleted complexes. To overcome limitation, we used molecular dynamics-based approach determine inter-subunit free energies in available human dimer their apo forms, which generated silico . GTPase active subunits SEPT2 SEPT7, SEPT6, was identified stabilizing element G interface it is coordinated at its ribose ring amino acids. Removal GDP from SEPT7 results flipping Arg residue disruption an extensive hydrogen bond network unique element, concomitant with decreased affinity.

Language: Английский

The evolutionary origins and ancestral features of septins DOI Creative Commons

Samed Delic,

Brent Shuman,

Shoken Lee

et al.

Frontiers in Cell and Developmental Biology, Journal Year: 2024, Volume and Issue: 12

Published: June 26, 2024

Septins are a family of membrane-associated cytoskeletal guanine-nucleotide binding proteins that play crucial roles in various cellular processes, such as cell division, phagocytosis, and organelle fission. Despite their importance, the evolutionary origins ancestral function septins remain unclear. In opisthokonts, form five distinct groups orthologs, with subunits from multiple assembling into heteropolymers, thus supporting diverse molecular functions. Recent studies have revealed also conserved algae protists, indicating an ancient origin last eukaryotic common ancestor. However, phylogenetic relationships among across eukaryotes remained Here, we expanded list non-opisthokont septins, including previously unrecognized glaucophyte algae. Constructing rooted tree 254 total observed bifurcation between major opisthokont septin clades. Within identified three subclades: Group 6 representing chlorophyte green (6A mostly for species single 6B septins), 7 chlorophytes, heterokonts, haptophytes, chrysophytes, rhodophytes, 8 ciliates. Glaucophyte some ciliate formed orphan lineages in-between all other outgroup. Combining ancestral-sequence reconstruction AlphaFold predictions, tracked structural evolution eukaryotes. GTPase domain, GAP-like arginine finger within G-interface at least one most algal species. This residue is required homodimerization Chlamydomonas septin, its loss coincided duplication events lineages. The often accompanied by emergence α0 helix, known NC-interface interaction motif, potentially signifying diversification septin-septin mechanisms homo-dimerization to hetero-oligomerization. Lastly, found amphipathic helices groups, suggesting membrane trait. Coiled-coil domains were broadly distributed, while transmembrane 6A 7. summary, this study advances our understanding distribution groupings, shedding light on features, potential function, early evolution.

Language: Английский

Citations

7
The structure of a tetrameric septin complex reveals a hydrophobic element essential for NC-interface integrity DOI Creative Commons
Benjamin Grupp, Lukas Denkhaus, S. Gerhardt

et al.

Communications Biology, Journal Year: 2024, Volume and Issue: 7(1)

Published: Jan. 6, 2024

Abstract The septins of the yeast Saccharomyces cerevisiae assemble into hetero-octameric rods by alternating interactions between neighboring G-domains or N- and C-termini, respectively. These polymerize end to apolar filaments, forming a ring beneath prospective new bud that expands during cell cycle an hourglass structure. finally splits cytokinesis double ring. Understanding these transitions as well plasticity higher order assemblies requires detailed knowledge underlying structures. Here we present first X-ray crystal structure tetrameric Shs1-Cdc12-Cdc3-Cdc10 complex at resolution 3.2 Å. Close inspection NC-interfaces this other septin structures reveals conserved contact motif is essential for NC-interface integrity human in vivo vitro. Using combination with AlphaFold-Multimer allowed us propose model octameric rod.

Language: Английский

Citations

5
An in silico approach to determine inter‐subunit affinities in human septin complexes DOI Creative Commons
Benjamin Grupp, Justin A. Lemkul, Thomas Gronemeyer

et al.

Cytoskeleton, Journal Year: 2023, Volume and Issue: 80(7-8), P. 141 - 152

Published: Feb. 27, 2023

The septins are a conserved family of filament-forming guanine nucleotide binding proteins, often named the fourth component cytoskeleton. Correctly assembled septin structures required for essential intracellular processes such as cytokinesis, vesicular transport, polarity establishment, and cellular adhesion. Structurally, belong to P-Loop NTPases but they do not mediate signals effectors through GTP hydrolysis. hydrolysis believed contribute complex integrity, biochemical approaches addressing this topic hampered by stability complexes after recombinant expression lack nucleotide-depleted complexes. To overcome limitation, we used molecular dynamics-based approach determine inter-subunit free energies in available human dimer their apo forms, which generated silico. GTPase active subunits SEPT2 SEPT7, SEPT6, was identified stabilizing element G interface. Removal GDP from SEPT7 results flipping Arg residue disruption an extensive hydrogen bond network unique element, concomitant with decreased affinity. Based on these findings propose singular "lock-hydrolysis" mechanism filaments.

Language: Английский

Citations

9
Effect of 11-Deoxycorticosterone in the Transcriptomic Response to Stress in Rainbow Trout Skeletal Muscle DOI Open Access
Rodrigo Zuloaga, Daniela Aravena-Canales, Jorge E. Aedo

et al.

Genes, Journal Year: 2023, Volume and Issue: 14(2), P. 512 - 512

Published: Feb. 17, 2023

In aquaculture, many stressors can negatively affect growth in teleosts. It is believed that cortisol performs glucocorticoid and mineralocorticoid functions because teleosts do not synthesize aldosterone. However, recent data suggest 11-deoxycorticosterone (DOC) released during stress events may be relevant to modulate the compensatory response. To understand how DOC modifies skeletal muscle molecular response, we carried out a transcriptomic analysis. Rainbow trout (Oncorhynchus mykiss) were intraperitoneally treated with physiological doses of individuals pretreated mifepristone (glucocorticoid receptor antagonist) or eplerenone (mineralocorticoid antagonist). RNA was extracted from muscles, cDNA libraries constructed vehicle, DOC, mifepristone, plus eplerenone, groups. The RNA-seq analysis revealed 131 differentially expressed transcripts (DETs) induced by respect vehicle group, mainly associated contraction, sarcomere organization, cell adhesion. addition, versus 122 DETs related differentiation. analysis, 133 autophagosome assembly, circadian regulation gene expression, transcription pol II promoter. These analyses indicate has function response whose action modulated GR MR complementary cortisol.

Language: Английский

Citations

6
The Evolutionary Origins and Ancestral Features of Septins DOI Creative Commons

Samed Delic,

Brent Shuman,

Shoken Lee

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: March 27, 2024

ABSTRACT Septins are a family of membrane-associated cytoskeletal GTPases that play crucial roles in various cellular processes, such as cell division, phagocytosis, and organelle fission. Despite their importance, the evolutionary origins ancestral function septins remain unclear. In opisthokonts, form five distinct groups orthologs, with subunits from multiple assembling into heteropolymers, thus supporting diverse molecular functions. Recent studies have revealed also conserved algae protists, indicating an ancient origin last eukaryotic common ancestor. However, phylogenetic relationships among across eukaryotes remained Here, we expanded list non-opisthokont septins, including previously unrecognized rhodophyte red glaucophyte algae. Constructing rooted tree 254 total observed bifurcation between major opisthokont septin clades. Within identified three subclades: Group 6 representing chlorophyte green (6A mostly for species single 6B septins), 7 chlorophytes, heterokonts, haptophytes, chrysophytes, rhodophytes, 8 ciliates. Glaucophyte some ciliate formed orphan lineages in-between all other outgroup. Combining ancestral-sequence reconstruction AlphaFold predictions, tracked structural evolution eukaryotes. GTPase domain, GAP-like arginine finger within G-interface at least one most algal species. This residue is required homodimerization Chlamydomonas septin, its loss coincided duplication events lineages. The often accompanied by emergence α0 helix, known NC-interface interaction motif, potentially signifying diversification septin-septin mechanisms homo-dimerization to hetero-oligomerization. Lastly, found amphipathic helices groups, suggesting curvature-sensing trait proteins. Coiled-coil domains were broadly distributed, while transmembrane 6A 7. summary, this study advances our understanding distribution groupings, shedding light on features, potential function, early evolution.

Language: Английский

Citations

2
Septins as key players in spermatogenesis, fertilisation and pre-implantation embryogenic cytoplasmic dynamics DOI Creative Commons

Hana Al-Ali,

Amna Baig,

Rayyah R. Alkhanjari

et al.

Cell Communication and Signaling, Journal Year: 2024, Volume and Issue: 22(1)

Published: Oct. 28, 2024

Septins are a family of cytokinesis-related proteins involved in regulating cytoskeletal design, cell morphology, and tissue morphogenesis. Apart from cytokinesis, as fourth component cytoskeleton, septins aid forming scaffolds, vesicle sorting membrane stability. They also known to be the regulation intracellular calcium (Ca2+) via STIM/Orai complex. Infertility affects ~ 15% couples globally, while male infertility 7% men. Global pregnancy live birth rates following fertility treatment remain relatively low, there has been an observable decline parameters over past 60 years. Low success can attributed poor embryonic development, sperm fertilisation defects. While studies few years have provided evidence for role related processes, functional its complexes cellular processes such oocyte activation, fertilization, maturation not completely understood. This review summarizes available knowledge on spermatogenesis activation Ca2+ regulation, dynamics throughout pre-implantation development. We aim identify currently less mechanisms by which regulate these immensely important with view identifying areas investigation that would benefit our understanding reproductive biology, but provide potential avenues improve current methods treatment.

Language: Английский

Citations

2
The Presence of Septin Proteins in the Neuromuscular Junction of Somatic Muscle in the Earthworm Lumbricus terrestris DOI

L. F Nurullin,

Evgenii Volkov

Биофизика, Journal Year: 2024, Volume and Issue: 69(5), P. 1011 - 1017

Published: Oct. 15, 2024

Language: Английский

Citations

0
Dysregulation of septin cytoskeletal organization in the trabecular meshwork contributes to ocular hypertension DOI Creative Commons
Rupalatha Maddala,

Pallavi Gorijavolu,

Levi K Lankford

et al.

JCI Insight, Journal Year: 2024, Volume and Issue: 9(23)

Published: Dec. 5, 2024

Ocular hypertension, believed to result partly from increased contractile activity, cell adhesive interactions, and stiffness within the trabecular meshwork (TM), is a major risk factor for glaucoma, leading cause of blindness. However, identity molecular mechanisms governing organization actomyosin interactions in TM remains limited. Based on our previous findings, which proteomics analyses revealed elevated levels septins, including septin-9 human cells treated with ocular hypertensive agent dexamethasone, here, we evaluated effects overexpression, deficiency, pharmacological targeting cells. These studies demonstrated profound impact organization, adhesion, contraction, phagocytosis. Overexpression raised intraocular pressure (IOP) mice, while inhibition permeability. In addition, replicated significant association between common variant (rs9038) SEPT9 IOP Genetic Epidemiology Research Adult Healthy Aging (GERA) cohort. Collectively, these data reveal link dysregulated septin cytoskeletal IOP, likely due enhanced fibrotic activity. This suggests that cytoskeleton could offer novel approach lowering patients glaucoma.

Language: Английский

Citations

0
The Presence of Septin Proteins in the Neuromuscular Junction of Somatic Muscle in the Earthworm Lumbricus terrestris DOI
Л. Ф. Нуруллин,

Е. М. Волков

BIOPHYSICS, Journal Year: 2024, Volume and Issue: 69(5), P. 876 - 881

Published: Oct. 1, 2024

Language: Английский

Citations

0
Estudos estruturais de complexos de septinas analisados por microscopia eletrônica de transmissão DOI Creative Commons

Déborah Cezar Mendonça

Published: May 19, 2023

Septinas são GTPases do citoesqueleto capazes de se associar na forma heterocomplexos, geralmente hexâmeros ou octâmeros, que polimerizam em filamentos subsequentemente organizam estruturas mais complexas como anéis e redes.Elas estão envolvidas uma série importantes processos intracelulares incluindo divisão celular, tráfego vesículas, exocitose, entre outros.Em humanos, alterações no padrão expressão dessas proteínas a presença mutações relacionadas doenças, alguns tipos câncer desordens neurológicas as doenças Parkinson Alzheimer.Entretanto, aspectos mecânicos ainda não totalmente compreendidos, os heterocomplexos agrupam corretamente.Neste trabalho, foi possível estudar complexos septinas humanas urocordado C. intestinalis usando microscopia eletrônica transmissão.Para ambos, ordem dos hexaméricos (compostos pelas 2, 6 7) determinada, concluindo SEPT2 dois organismos está localizada extremidade complexo (2-6-7-7-6-2).Especificamente para o humano, esse resultado comprova hexâmero anteriormente aceita literatura estava invertida, correção dessa informação possibilitou correlação humano com outros organismos, além explicar octâmeros podem compor mesmo filamento.Para obter detalhes estruturais complexos, foram resolvidas por Crio-ME, resolução 3.6 Å 3.3 intestinalis.A análise da estrutura permitiu compreensão moleculares interface formada SEPT6 SEPT7 maior comparada à cristalográfica precedente.A NC apresenta cavidade é fechada sua base através das hélices α0 duas subunidades, incluem região polibásica.Elas mantidas enterradas interior interação desses resíduos básicos cotovelo formado α5 α6 subunidade vizinha.A observação espaço deixado pela estabilizar hélice posição auxiliam capaz sofrer mudança conformacional.Adicionalmente, observar flexibilidade um todo direção específica, pode estar relacionada maneira interagem membrana.No caso intestinalis, estrutural três presentes inéditas mostra elas nível molecular evolutivamente conservadas

Citations

0