Faculty Opinions recommendation of Gamma-tubulin37C and gamma-tubulin ring complex protein 75 are essential for bicoid RNA localization during drosophila oogenesis.

Abstract Recently, two cases of complete remission of classical Hodgkin lymphoma (cHL) and follicular lymphoma (FL) after SARS-CoV-2 infection were reported. However, the precise molecular mechanism of this rare event is yet to be understood. Here, we hypothesize a potential anti-tumor immune response of SARS-CoV-2 and based on computational approach show that (i) SARS-CoV-2 Spike-RBD may bind to extracellular domains of CD15, CD27, CD45, and CD152 receptors of cHL or FL, (ii) upon internalization, SARS-CoV-2 membrane (M) protein and Orf3a may bind to gamma-tubulin complex component 3 (GCP3) at its tubulin gamma-1 chain (TUBG1) binding site, (iii) M protein may also interact with TUBG1 blocking its binding to GCP3, (iv) both M and Orf3a may render the GCP2-GCP3 lateral binding where M possibly interacts with GCP2 at its GCP3 binding site and Orf3a to GCP3 at its GCP2 interacting residues, (v) interactions of M and Orf3a with these gamma-tubulin ring complex components potentially block the initial process of microtubule nucleation, leading to cell cycle arrest and apoptosis, (vi) Spike-RBD may also interact with and block PD-1 signaling similar to pembrolizumab and nivolumab like monoclonal antibodies and may induce B-cell apoptosis and remission, (vii) finally, the TRADD interacting PVQLSY motif of Epstein-Barr virus LMP-1, that is responsible for NF-kB mediated oncogenesis, potentially interacts with SARS-CoV-2 Mpro, nsp7, nsp10, and Spike proteins and may regulate the LMP-1 mediated cell proliferation. Taken together, our results suggest a possible therapeutic potential of SARS-CoV-2 in proliferative disorders.

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Identification of an Spc110p-related protein in vertebrates

Journal of Cell Science ◽

10.1242/jcs.110.20.2533 ◽

1997 ◽

Vol 110 (20) ◽

pp. 2533-2545 ◽

Cited By ~ 1

Author(s):

A.M. Tassin ◽

C. Celati ◽

M. Paintrand ◽

M. Bornens

Keyword(s):

Mammalian Cells ◽

Spindle Pole Body ◽

Spindle Pole ◽

Partial Purification ◽

Related Protein ◽

Microtubule Nucleation ◽

Pole Body ◽

Egg Extract ◽

Ring Complex ◽

Gamma Tubulin

Although varying in size and complexity, centrosomes have conserved functions throughout the evolutionary range of eukaryotes, and thus may display conserved components. In this work, we took advantage of the recent advances in the isolation of the budding yeast spindle pole body, the development of specific immunological probes and the molecular characterisation of genes involved in spindle pole body duplication or assembly. Screening a monoclonal antibody library against Saccharomyces cerevisiae spindle pole body components, we found that two monoclonal antibodies, directed against two different parts of the yeast Spc110p, decorate the centrosome from mammalian cells in an asymmetrical manner. Western blot experiments identified a 100 kDa protein specifically enriched in centrosome preparations from human cells. This protein is phosphorylated during mitosis and is tightly associated with the centrosome: only denaturing conditions such as 8 M urea were able to solubilise it. Purified immunoglobulins directed against Spc110p inhibit microtubule nucleation on isolated human centrosomes, using brain phosphocellulose-tubulin or Xenopus egg extract tubulin. This result suggested that the centrosomal 100 kDa protein could be involved in a microtubule nucleation complex. To test this hypothesis, we turned to Xenopus species, in which mAb anti-Spc110p decorated centrosomes from somatic cells and identified a 116 kDa protein in egg extract. We performed a partial purification of the gamma-tubulin-ring complex from egg extract. Sucrose gradient sedimentation, immunoprecipitation and native gels demonstrated that the Xenopus 116 kDa protein and gamma-tubulin were found in the same complex. Altogether, these results suggest the existence of an yeast Spc110-related protein in vertebrate centrosomes which is involved in microtubule nucleation.

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The γ-tubulin complex protein GCP6 is crucial for spindle morphogenesis but not essential for microtubule reorganization inArabidopsis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1912240116 ◽

2019 ◽

Vol 116 (52) ◽

pp. 27115-27123 ◽

Cited By ~ 1

Author(s):

Huiying Miao ◽

Rongfang Guo ◽

Junlin Chen ◽

Qiaomei Wang ◽

Yuh-Ru Julie Lee ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Vegetative Growth ◽

Functional Form ◽

Plant Cells ◽

Wild Type ◽

Gene Encoding ◽

Small Complex ◽

Complex Protein ◽

Ring Complex ◽

Insight Into

γ-Tubulin typically forms a ring-shaped complex with 5 related γ-tubulin complex proteins (GCP2 to GCP6), and this γ-tubulin ring complex (γTuRC) serves as a template for microtubule (MT) nucleation in plants and animals. While the γTuRC takes part in MT nucleation in most eukaryotes, in fungi such events take place robustly with just the γ-tubulin small complex (γTuSC) assembled by γ-tubulin plus GCP2 and GCP3. To explore whether the γTuRC is the sole functional γ-tubulin complex in plants, we generated 2 mutants of theGCP6gene encoding the largest subunit of the γTuRC inArabidopsis thaliana. Both mutants showed similar phenotypes of dwarfed vegetative growth and reduced fertility. Thegcp6mutant assembled the γTuSC, while the wild-type cells had GCP6 join other GCPs to produce the γTuRC. Although thegcp6cells had greatly diminished γ-tubulin localization on spindle MTs, the protein was still detected there. Thegcp6cells formed spindles that lacked MT convergence and discernable poles; however, they managed to cope with the challenge of MT disorganization and were able to complete mitosis and cytokinesis. Our results reveal that the γTuRC is not the only functional form of the γ-tubulin complex for MT nucleation in plant cells, and that γ-tubulin-dependent, but γTuRC-independent, mechanisms meet the basal need of MT nucleation. Moreover, we show that the γTuRC function is more critical for the assembly of spindle MT array than for the phragmoplast. Thus, our findings provide insight into acentrosomal MT nucleation and organization.

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