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2.
Angew Chem Int Ed Engl ; 61(41): e202209105, 2022 10 10.
Artículo en Inglés | MEDLINE | ID: mdl-35901418

RESUMEN

The choanoflagellate Salpingoeca rosetta is an important model system to study the evolution of multicellularity. In this study we developed a new, modular, and scalable synthesis of sulfonolipid IOR-1A (six steps, 27 % overall yield), which acts as bacterial inhibitor of rosette formation in S. rosetta. The synthesis features a decarboxylative cross-coupling reaction of a sulfonic acid-containing tartaric acid derivative with alkyl zinc reagents. Synthesis of 15 modified IOR-1A derivatives, including fluorescent and photoaffinity-based probes, allowed quantification of IOR-1A, localization studies within S. rosetta cells, and evaluation of structure-activity relations. In a proof of concept study, an inhibitory bifunctional probe was employed in proteomic profiling studies, which allowed to deduce binding partners in bacteria and S. rosetta. These results showcase the power of synthetic chemistry to decipher the biochemical basis of cell differentiation processes within S. rosetta.


Asunto(s)
Coanoflagelados , Diferenciación Celular , Lípidos , Proteómica , Ácidos Sulfónicos , Zinc
4.
Nat Microbiol ; 7(3): 397-410, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35165385

RESUMEN

Contractile injection systems (CISs) are phage tail-like nanomachines, mediating bacterial cell-cell interactions as either type VI secretion systems (T6SSs) or extracellular CISs (eCISs). Bioinformatic studies uncovered a phylogenetic group of hundreds of putative CIS gene clusters that are highly diverse and widespread; however, only four systems have been characterized. Here we studied a putative CIS gene cluster in the marine bacterium Algoriphagus machipongonensis. Using an integrative approach, we show that the system is compatible with an eCIS mode of action. Our cryo-electron microscopy structure revealed several features that differ from those seen in other CISs: a 'cap adaptor' located at the distal end, a 'plug' exposed to the tube lumen, and a 'cage' formed by massive extensions of the baseplate. These elements are conserved in other CISs, and our genetic tools identified that they are required for assembly, cargo loading and function. Furthermore, our atomic model highlights specific evolutionary hotspots and will serve as a framework for understanding and re-engineering CISs.


Asunto(s)
Sistemas de Secreción Tipo VI , Bacteroidetes , Microscopía por Crioelectrón , Filogenia , Sistemas de Secreción Tipo VI/química , Sistemas de Secreción Tipo VI/genética
5.
Chemistry ; 28(8): e202103883, 2022 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-34863043

RESUMEN

We have analyzed the abundance of bacterial sulfonosphingolipids, including rosette-inducing factors (RIFs), in seven bacterial prey strains by using high-resolution tandem mass spectrometry (HRMS2 ) and molecular networking (MN) within the Global Natural Product Social Molecular Networking (GNPS) web platform. Six sulfonosphingolipids resembling RIFs were isolated and their structures were elucidated based on comparative MS and NMR studies. Here, we also report the first total synthesis of two RIF-2 diastereomers and one congener in 15 and eight synthetic steps, respectively. For the total synthesis of RIF-2 congeners, we employed a decarboxylative cross-coupling reaction to synthesize the necessary branched α-hydroxy fatty acids, and the Garner-aldehyde approach to generate the capnine base carrying three stereogenic centers. Bioactivity studies in the choanoflagellate Salpingoeca rosetta revealed that the rosette inducing activity of RIFs is inhibited dose dependently by the co-occurring sulfonosphingolipid sulfobacins D and F and that activity of RIFs is specific for isolates obtained from Algoriphagus.


Asunto(s)
Bacteroidetes , Coanoflagelados , Esfingolípidos/química , Bacterias , Bacteroidetes/química , Coanoflagelados/química , Espectroscopía de Resonancia Magnética , Espectrometría de Masas en Tándem
6.
Cell ; 184(26): 6217-6221, 2021 12 22.
Artículo en Inglés | MEDLINE | ID: mdl-34942095

RESUMEN

Virtual interviewing has become ubiquitous with the academic job market. Here, we highlight the best practices for candidates and departments to consider when using virtual interviewing. We propose how virtual interviews can be leveraged and adapted for hybrid academic job searches combining virtual and in-person activities in a post-pandemic world.


Asunto(s)
Empleo , Entrevistas como Asunto , Universidades , COVID-19/epidemiología , Selección de Profesión , Docentes , Humanos
7.
Pathog Dis ; 79(5)2021 06 03.
Artículo en Inglés | MEDLINE | ID: mdl-34048540

RESUMEN

While it is commonly thought that microaggressions are isolated incidents, microaggressions are ingrained throughout the academic research institution (Young, Anderson and Stewart 2015; Lee et al. 2020). Persons Excluded from science because of Ethnicity and Race (PEERs) frequently experience microaggressions from various academicians, including graduate students, postdocs and faculty (Asai 2020; Lee et al. 2020). Here, we elaborate on a rationale for concrete actions to cope with and diminish acts of microaggressions that may otherwise hinder the inclusion of PEERs. We encourage Science, Technology, Engineering and Mathematics (STEM) departments and leadership to affirm PEER scholar identities and promote allyship by infusing sensitivity, responsiveness and anti-bias awareness.


Asunto(s)
Microagresión , Racismo/prevención & control , Ciencia/organización & administración , Ingeniería , Humanos , Matemática , Estudiantes , Tecnología , Universidades
8.
Trends Biochem Sci ; 46(5): 345-348, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33622580

RESUMEN

Scientific success is mainly supported by mentoring, which often occurs through face-to-face interactions. Changes to the research environment incurred by the Coronavirus 2019 (COVID-19) pandemic have necessitated mentorship adaptations. Here, we describe how mentors can broaden their mentorship to support trainee growth and provide reassurance about trainee development amid uncertain circumstances.


Asunto(s)
COVID-19/epidemiología , Tutoría , Pandemias , Investigadores/educación , SARS-CoV-2 , Humanos
9.
Cell ; 183(3): 568-575, 2020 10 29.
Artículo en Inglés | MEDLINE | ID: mdl-33125882

RESUMEN

We identify problematic areas throughout the Science, Technology, Engineering and Mathematics (STEM) pipeline that perpetuate racial disparities in academia. Distinct ways to curtail these disparities include early exposure and access to resources, supportive mentoring networks and comprehensive training programs specifically for racially minoritized students and trainees at each career stage. These actions will revitalize the STEM pipeline.


Asunto(s)
Ingeniería/educación , Matemática/educación , Ciencia/educación , Tecnología/educación , Educación de Postgrado , Humanos , Universidades
10.
Sci Transl Med ; 12(527)2020 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-31969487

RESUMEN

Heightened secretion of protumorigenic effector proteins is a feature of malignant cells. Yet, the molecular underpinnings and therapeutic implications of this feature remain unclear. Here, we identify a chromosome 1q region that is frequently amplified in diverse cancer types and encodes multiple regulators of secretory vesicle biogenesis and trafficking, including the Golgi-dedicated enzyme phosphatidylinositol (PI)-4-kinase IIIß (PI4KIIIß). Molecular, biochemical, and cell biological studies show that PI4KIIIß-derived PI-4-phosphate (PI4P) synthesis enhances secretion and accelerates lung adenocarcinoma progression by activating Golgi phosphoprotein 3 (GOLPH3)-dependent vesicular release from the Golgi. PI4KIIIß-dependent secreted factors maintain 1q-amplified cancer cell survival and influence prometastatic processes in the tumor microenvironment. Disruption of this functional circuitry in 1q-amplified cancer cells with selective PI4KIIIß antagonists induces apoptosis and suppresses tumor growth and metastasis. These results support a model in which chromosome 1q amplifications create a dependency on PI4KIIIß-dependent secretion for cancer cell survival and tumor progression.


Asunto(s)
Adenocarcinoma del Pulmón/metabolismo , Cromosomas Humanos Par 1/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Adenocarcinoma del Pulmón/genética , Animales , Cromosomas Humanos Par 1/genética , Ensayo de Inmunoadsorción Enzimática , Aparato de Golgi/metabolismo , Humanos , Técnicas In Vitro , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Fosfotransferasas (Aceptor de Grupo Alcohol)/antagonistas & inhibidores , Microtomografía por Rayos X
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