scholarly journals A SAS-6-Like Protein Suggests that the Toxoplasma Conoid Complex Evolved from Flagellar Components

2013 ◽  
Vol 12 (7) ◽  
pp. 1009-1019 ◽  
Author(s):  
Jessica Cruz de Leon ◽  
Nicole Scheumann ◽  
Wandy Beatty ◽  
Josh R. Beck ◽  
Johnson Q. Tran ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Common Ancestor ◽  
Coiled Coil ◽  
Apicomplexan Parasite ◽  
Last Common Ancestor ◽  
Cell Cytoplasm ◽  
Content Type ◽  
Conserved Domain ◽  
Coiled Coil Domain ◽  
Order Structures

ABSTRACT SAS-6 is required for centriole biogenesis in diverse eukaryotes. Here, we describe a novel family of SAS-6-like (SAS6L) proteins that share an N-terminal domain with SAS-6 but lack coiled-coil tails. SAS6L proteins are found in a subset of eukaryotes that contain SAS-6, including diverse protozoa and green algae. In the apicomplexan parasite Toxoplasma gondii , SAS-6 localizes to the centriole but SAS6L is found above the conoid, an enigmatic tubulin-containing structure found at the apex of a subset of alveolate organisms. Loss of SAS6L causes reduced fitness in Toxoplasma . The Trypanosoma brucei homolog of SAS6L localizes to the basal-plate region, the site in the axoneme where the central-pair microtubules are nucleated. When endogenous SAS6L is overexpressed in Toxoplasma tachyzoites or Trypanosoma trypomastigotes, it forms prominent filaments that extend through the cell cytoplasm, indicating that it retains a capacity to form higher-order structures despite lacking a coiled-coil domain. We conclude that although SAS6L proteins share a conserved domain with SAS-6, they are a functionally distinct family that predates the last common ancestor of eukaryotes. Moreover, the distinct localization of the SAS6L protein in Trypanosoma and Toxoplasma adds weight to the hypothesis that the conoid complex evolved from flagellar components.

scholarly journals Mitochondrial Contact Site and Cristae Organization System and F 1 F O -ATP Synthase Crosstalk Is a Fundamental Property of Mitochondrial Cristae

mSphere ◽  
2021 ◽  
Author(s):  
Lawrence Rudy Cadena ◽  
Ondřej Gahura ◽  
Brian Panicucci ◽  
Alena Zíková ◽  
Hassan Hashimi
Keyword(s):  
Infectious Diseases ◽  
Trypanosoma Brucei ◽  
Atp Synthase ◽  
Common Ancestor ◽  
Fundamental Property ◽  
Last Common Ancestor ◽  
Contact Site ◽  
Content Type ◽  
Etiological Agents

Mitochondria have undergone profound diversification in separate lineages that have radiated since the last common ancestor of eukaryotes some eons ago. Most eukaryotes are unicellular protists, including etiological agents of infectious diseases, like Trypanosoma brucei .

scholarly journals CMF22 Is a Broadly Conserved Axonemal Protein and Is Required for Propulsive Motility in Trypanosoma brucei

2013 ◽  
Vol 12 (9) ◽  
pp. 1202-1213 ◽  
Author(s):  
HoangKim T. Nguyen ◽  
Jaspreet Sandhu ◽  
Gerasimos Langousis ◽  
Kent L. Hill
Keyword(s):  
Trypanosoma Brucei ◽  
Common Ancestor ◽  
Normal Development ◽  
Potential Interaction ◽  
Content Type ◽  
Motility Regulation ◽  
Regulatory Complex ◽  
Core Components ◽  
Insight Into ◽  
Flagellar Axoneme

ABSTRACT The eukaryotic flagellum (or cilium) is a broadly conserved organelle that provides motility for many pathogenic protozoa and is critical for normal development and physiology in humans. Therefore, defining core components of motile axonemes enhances understanding of eukaryotic biology and provides insight into mechanisms of inherited and infectious diseases in humans. In this study, we show that component of motile flagella 22 (CMF22) is tightly associated with the flagellar axoneme and is likely to have been present in the last eukaryotic common ancestor. The CMF22 amino acid sequence contains predicted IQ and A TPase a ssociated with a variety of cellular a ctivities (AAA) motifs that are conserved among CMF22 orthologues in diverse organisms, hinting at the importance of these domains in CMF22 function. Knockdown by RNA interference (RNAi) and rescue with an RNAi-immune mRNA demonstrated that CMF22 is required for propulsive cell motility in Trypanosoma brucei . Loss of propulsive motility in CMF22-knockdown cells was due to altered flagellar beating patterns, rather than flagellar paralysis, indicating that CMF22 is essential for motility regulation and likely functions as a fundamental regulatory component of motile axonemes. CMF22 association with the axoneme is weakened in mutants that disrupt the nexin-dynein regulatory complex, suggesting potential interaction with this complex. Our results provide insight into the core machinery required for motility of eukaryotic flagella.

scholarly journals Rab11 Function in Trypanosoma brucei: Identification of Conserved and Novel Interaction Partners

2011 ◽  
Vol 10 (8) ◽  
pp. 1082-1094 ◽  
Author(s):  
Carme Gabernet-Castello ◽  
Kelly N. DuBois ◽  
Camus Nimmo ◽  
Mark C. Field
Keyword(s):  
Trypanosoma Brucei ◽  
Intracellular Transport ◽  
Homo Sapiens ◽  
Coiled Coil ◽  
Membrane Composition ◽  
Content Type ◽  
Evolutionarily Conserved ◽  
Interaction Partners ◽  
Hybrid Screening

ABSTRACT The Ras-like GTPase Rab11 is implicated in multiple aspects of intracellular transport, including maintenance of plasma membrane composition and cytokinesis. In metazoans, these functions are mediated in part via coiled-coil Rab11-interacting proteins (FIPs) acting as Rab11 effectors. Additional interaction between Rab11 and the exocyst subunit Sec15 connects Rab11 with exocytosis. We find that FIPs are metazoan specific, suggesting that other factors mediate Rab11 functions in nonmetazoans. We examined Rab11 interactions in Trypanosoma brucei , where endocytosis is well studied and the role of Rab11 in recycling well documented. TbSec15 and TbRab11 interact, demonstrating evolutionary conservation. By yeast two-hybrid screening, we identified additional Rab11 interaction partners. Tb927.5.1640 (designated RBP74) interacted with both Rab11 and Rab5. RBP74 shares a coiled-coil architecture with metazoan FIPs but is unrelated by sequence and appears to play a role in coordinating endocytosis and recycling. A second coiled-coil protein, Tb09.211.4830 (TbAZI1), orthologous to AZI1 in Homo sapiens , interacts exclusively with Rab11. AZI1 is restricted to taxa with motile cilia/flagella. These data suggest that Rab11 functions are mediated by evolutionarily conserved (i.e., AZI1 and Sec15) and potentially lineage-specific (RBP74) interactions essential for the integration of the endomembrane system.

scholarly journals The CARD-CC/Bcl10/paracaspase signaling complex is functionally conserved since the last common ancestor of Planulozoa

2016 ◽  
Author(s):  
Jens Staal ◽  
Yasmine Driege ◽  
Alice Borghi ◽  
Paco Hulpiau ◽  
Laurens Lievens ◽  
...  
Keyword(s):  
Common Ancestor ◽  
Coiled Coil ◽  
Sh2 Domain ◽  
Last Common Ancestor ◽  
Signaling Proteins ◽  
Downstream Signaling ◽  
Signaling Complex ◽  
Functional Analyses

AbstractType 1 paracaspases originated in the Ediacaran geological period before the last common ancestor of bilaterians and cnidarians (Planulozoa). Cnidarians have several paralog type 1 paracaspases, type 2 paracaspases, and a homolog of Bcl10. Notably in bilaterians, lineages like nematodes and insects lack Bcl10 whereas other lineages such as vertebrates, hemichordates, annelids and mollusks have a Bcl10 homolog. A survey of invertebrate CARD-coiled-coil (CC) domain homologs of CARMA/CARD9 revealed such homologs only in species with Bcl10, indicating an ancient co-evolution of the entire CARD-CC/Bcl10/MALT1-like paracaspase (CBM) complex. Furthermore, vertebrate-like Syk/Zap70 tyrosine kinase homologs with the ITAM-binding SH2 domain were found in invertebrate organisms with CARD-CC/Bcl10, indicating that this pathway might be the original user of the CBM complex. We also established that the downstream signaling proteins TRAF2 and TRAF6 are functionally conserved in Cnidaria. There also seems to be a correlation where invertebrates with CARD-CC and Bcl10 have type 1 paracaspases which are more similar to the paracaspases found in vertebrates. A proposed evolutionary scenario includes at least two ancestral type 1 paracaspase paralogs in the planulozoan last common ancestor, where at least one paralog usually is dependent on CARD-CC/Bcl10 for its function. Functional analyses of invertebrate type 1 paracaspases and Bcl10 homologs support this scenario and indicate an ancient origin of the CARD-CC/Bcl10/paracaspase signaling complex. Results from cnidarians, nematodes and mice also suggest an ancient neuronal role for the type 1 paracaspases.

scholarly journals Comparative Genomic Analysis of Mycobacteriaceae Reveals Horizontal Gene Transfer-Mediated Evolution of the CRISPR-Cas System in the Mycobacterium tuberculosis Complex

mSystems ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Anoop Singh ◽  
Mohita Gaur ◽  
Vishal Sharma ◽  
Palak Khanna ◽  
Ankur Bothra ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Common Ancestor ◽  
Genomic Analysis ◽  
Comparative Genomic Analysis ◽  
Comparative Genomic ◽  
Last Common Ancestor ◽  
Content Type ◽  
Type Iii

ABSTRACT Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) genes are conserved genetic elements in many prokaryotes, including Mycobacterium tuberculosis, the causative agent of tuberculosis. Although knowledge of CRISPR locus variability has been utilized in M. tuberculosis strain genotyping, its evolutionary path in Mycobacteriaceae is not well understood. In this study, we have performed a comparative analysis of 141 mycobacterial genomes and identified the exclusive presence of the CRISPR-Cas type III-A system in M. tuberculosis complex (MTBC). Our global phylogenetic analysis of CRISPR repeats and Cas10 proteins offers evidence of horizontal gene transfer (HGT) of the CRISPR-Cas module in the last common ancestor of MTBC and Mycobacterium canettii from a Streptococcus-like environmental bacterium. Additionally, our results show that the variation of CRISPR-Cas organization in M. tuberculosis lineages, especially in the Beijing sublineage of lineage 2, is due to the transposition of insertion sequence IS6110. The direct repeat (DR) region of the CRISPR-Cas locus acts as a hot spot for IS6110 insertion. We show in M. tuberculosis H37Rv that the repeat at the 5′ end of CRISPR1 of the forward strand is an atypical repeat made up partly of IS-terminal inverted repeat and partly CRISPR DR. By tracing an undetectable spacer sequence in the DR region, the two CRISPR loci could theoretically be joined to reconstruct the ancestral single CRISPR-Cas locus organization, as seen in M. canettii. This study retracing the evolutionary events of HGT and IS6110-driven genomic deletions helps us to better understand the strain-specific variations in M. tuberculosis lineages. IMPORTANCE Comparative genomic analysis of prokaryotes has led to a better understanding of the biology of several pathogenic microorganisms. One such clinically important pathogen is M. tuberculosis, the leading cause of bacterial infection worldwide. Recent evidence on the functionality of the CRISPR-Cas system in M. tuberculosis has brought back focus on these conserved genetic elements, present in many prokaryotes. Our study advances understanding of mycobacterial CRISPR-Cas origin and its diversity among the different species. We provide phylogenetic evidence of acquisition of CRISPR-Cas type III-A in the last common ancestor shared between MTBC and M. canettii, by HGT-mediated events. The most likely source of HGT was an environmental Firmicutes bacterium. Genomic mapping of the CRISPR loci showed the IS6110 transposition-driven variations in M. tuberculosis strains. Thus, this study offers insights into events related to the evolution of CRISPR-Cas in M. tuberculosis lineages.

Debunking two myths against vocal origins of language

2017 ◽  
Vol 18 (3) ◽  
pp. 376-401 ◽  
Author(s):  
Marcus Perlman
Keyword(s):  
Common Ancestor ◽  
Great Apes ◽  
Sound Symbolism ◽  
Vocal Behavior ◽  
Last Common Ancestor ◽  
Great Ape ◽  
Diverse Range ◽  
Content Type ◽  
Vocal Imitation ◽  
Breathing Apparatus

Gesture-first theories of language origins often raise two unsubstantiated arguments against vocal origins. First, they argue that great ape vocal behavior is highly constrained, limited to a fixed, species-typical repertoire of reflexive calls. Second, they argue that vocalizations lack any significant potential to ground meaning through iconicity, or resemblance between form and meaning. This paper reviews the considerable evidence that debunks these two “myths”. Accumulating evidence shows that the great apes exercise voluntary control over their vocal behavior, including their breathing apparatus, larynx, and supralaryngeal articulators. They are also able to learn new vocal behaviors, and even show some rudimentary ability for vocal imitation. In addition, an abundance of research demonstrates that the vocal modality affords rich potential for iconicity. People can understand iconicity in sound symbolism, and they can produce iconic vocalizations to communicate a diverse range of meanings. Thus, two of the primary arguments against vocal origins theories are not tenable. As an alternative, the paper concludes that the origins of language – going as far back as our last common ancestor with great apes – are rooted in iconicity in both gesture and vocalization.

TMCC3 localizes at the three-way junctions for the proper tubular network of the endoplasmic reticulum

2019 ◽  
Vol 476 (21) ◽  
pp. 3241-3260
Author(s):  
Sindhu Wisesa ◽  
Yasunori Yamamoto ◽  
Toshiaki Sakisaka
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Mammalian Cells ◽  
Coiled Coil ◽  
Transmembrane Domains ◽  
Domain Family ◽  
Coiled Coil Domain ◽  
U2os Cells ◽  
Er Membrane

The tubular network of the endoplasmic reticulum (ER) is formed by connecting ER tubules through three-way junctions. Two classes of the conserved ER membrane proteins, atlastins and lunapark, have been shown to reside at the three-way junctions so far and be involved in the generation and stabilization of the three-way junctions. In this study, we report TMCC3 (transmembrane and coiled-coil domain family 3), a member of the TEX28 family, as another ER membrane protein that resides at the three-way junctions in mammalian cells. When the TEX28 family members were transfected into U2OS cells, TMCC3 specifically localized at the three-way junctions in the peripheral ER. TMCC3 bound to atlastins through the C-terminal transmembrane domains. A TMCC3 mutant lacking the N-terminal coiled-coil domain abolished localization to the three-way junctions, suggesting that TMCC3 localized independently of binding to atlastins. TMCC3 knockdown caused a decrease in the number of three-way junctions and expansion of ER sheets, leading to a reduction of the tubular ER network in U2OS cells. The TMCC3 knockdown phenotype was partially rescued by the overexpression of atlastin-2, suggesting that TMCC3 knockdown would decrease the activity of atlastins. These results indicate that TMCC3 localizes at the three-way junctions for the proper tubular ER network.

scholarly journals The coiled-coil domain of EspA is essential for the assembly of the type III secretion translocon on the surface of enteropathogenic Escherichia coli. Vol. 274 (1999) 35969–35974

2005 ◽  
Vol 280 (19) ◽  
pp. 19436
Author(s):  
Robin M. Delahay ◽  
Stuart Knutton ◽  
Robert K. Shaw ◽  
Elizabeth L. Hartland ◽  
Mark J. Pallen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Type Iii Secretion ◽  
Coiled Coil ◽  
Enteropathogenic Escherichia Coli ◽  
Type Iii ◽  
Coiled Coil Domain

scholarly journals Experimental evidence for yawn contagion in orangutans (Pongo pygmaeus)

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Evy van Berlo ◽  
Alejandra P. Díaz-Loyo ◽  
Oscar E. Juárez-Mora ◽  
Mariska E. Kret ◽  
Jorg J. M. Massen
Keyword(s):  
Experimental Evidence ◽  
Common Ancestor ◽  
Great Apes ◽  
Pongo Pygmaeus ◽  
Last Common Ancestor ◽  
Contagious Yawning ◽  
Proximate Mechanism ◽  
Social Species ◽  
Ultimate Causation

AbstractYawning is highly contagious, yet both its proximate mechanism(s) and its ultimate causation remain poorly understood. Scholars have suggested a link between contagious yawning (CY) and sociality due to its appearance in mostly social species. Nevertheless, as findings are inconsistent, CY’s function and evolution remains heavily debated. One way to understand the evolution of CY is by studying it in hominids. Although CY has been found in chimpanzees and bonobos, but is absent in gorillas, data on orangutans are missing despite them being the least social hominid. Orangutans are thus interesting for understanding CY’s phylogeny. Here, we experimentally tested whether orangutans yawn contagiously in response to videos of conspecifics yawning. Furthermore, we investigated whether CY was affected by familiarity with the yawning individual (i.e. a familiar or unfamiliar conspecific and a 3D orangutan avatar). In 700 trials across 8 individuals, we found that orangutans are more likely to yawn in response to yawn videos compared to control videos of conspecifics, but not to yawn videos of the avatar. Interestingly, CY occurred regardless of whether a conspecific was familiar or unfamiliar. We conclude that CY was likely already present in the last common ancestor of humans and great apes, though more converging evidence is needed.

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