| 1. |
- Buvall, Lisa, 1976, et al.
(författare)
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Synaptopodin Is a Coincidence Detector of Tyrosine versus Serine/Threonine Phosphorylation for the Modulation of Rho Protein Crosstalk in Podocytes.
- 2017
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Ingår i: Journal of the American Society of Nephrology : JASN. - 1533-3450. ; 28:3, s. 837-851
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Tidskriftsartikel (refereegranskat)abstract
- Tyrosine and serine/threonine signal-transduction pathways influence many aspects of cell behavior, including the spatial and temporal regulation of the actin cytoskeleton. However, little is known about how input from diverse tyrosine and serine/threonine kinases is integrated to control Rho protein crosstalk and actin remodeling, which are critically important in podocyte health and disease. Here we unveil the proteolytically-regulated, actin organizing protein synaptopodin as a coincidence detector of tyrosine versus serine/threonine phosphorylation. We show that serine/threonine and tyrosine kinases duel for synaptopodin stability versus degradation. EGFR/Src-mediated tyrosine phosphorylation of synaptopodin in podocytes promotes binding to the serine/threonine phosphatase calcineurin. This leads to the loss of 14-3-3 binding, resulting in synaptopodin degradation, Vav2 activation, enhanced Rac1 signaling, and ultimate loss of stress fibers. Our studies reveal how synaptopodin, a single proteolytically-controlled protein, integrates antagonistic tyrosine versus serine/threonine phosphorylation events for the dynamic control of the actin cytoskeleton in podocytes.
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| 2. |
- Kulikovskiy, Maxim, et al.
(författare)
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Phylogenetic position of the diatom genus Geissleria Lange-Bertalot & Metzeltin and description of two new species from Siberian mountain lakes
- 2014
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Ingår i: Phytotaxa. - 1179-3163. ; 177:5, s. 249-260
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Tidskriftsartikel (refereegranskat)abstract
- Two new Geissleria species from Siberian mountain lakes Baikal and Frolikha are described based on molecular and morphological data. The two new species are Geissleria baicalosimilis Kulikovskiy, Gusev, Andreeva & Annenkova sp. nov. and G. frolikhiensis Kulikovskiy, Gusev, Andreeva & Annenkova sp. nov. According to partial 18S rDNA and rbcL gene fragment analyses, Geissleria does not belong to the large catch-all genus Navicula as it was previously thought. Morphological features such as slit like areolae without hymenes, presence of one isolated pore near the central nodule and presence of props in areolae and an annulus structure support this conclusion. Plastid morphology of Geissleria species is typical for the Cymbellales, with one large chloroplast divided into two plates lying one against each valve, connected by a broad column. All of our data show that Geissleria is most closely to the genus Placoneis, with which they share naviculoid symmetry. Given these results, Geissleria should be included in the order Cymbellales.
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| 3. |
- Zyubko, Tatyana, et al.
(författare)
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Efficient in vivo synthesis of lasso peptide pseudomycoidin proceeds in the absence of both the leader and the leader peptidase
- 2019
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Ingår i: Chemical Science. - : Royal Society of Chemistry (RSC). - 2041-6520 .- 2041-6539. ; 10:42, s. 9699-9707
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Tidskriftsartikel (refereegranskat)abstract
- Bacterial lasso peptides are made from linear ribosomally synthesized precursors by specific cleavage at the leader-core junction site of the precursor by a dedicated protease recognizing the leader, followed by cyclisation of the newly formed N-terminus of the core part with a side chain of the internal aspartic or glutamic residue catalyzed by a macrolactam synthetase. The resulting structure has a tail that is threaded and fixed inside the cycle formed. Here, we characterize a new lasso peptide, pseudomycoidin, encoded by Bacillus pseudomycoides DSM 12442. The most surprising and unique feature of pseudomycoidin is that it can be produced in vivo from the ribosomally synthesized core part by a macrolactam synthetase, in the absence of the leader protease. The minimalism of the pseudomycoidin synthesis system makes it a powerful model to generate pseudomycoidin-based lasso-peptide libraries and to study the poorly understood process of lasso formation. We detected two additional pseudomycoidin modifications: phosphorylation of a terminal residue that was previously observed in another lasso peptide, followed by glycosylation, which was not observed heretofore. We speculate that these bulky C-terminal modifications may help maintain the threaded lasso topology of the compound synthesized by the macrolactam synthetase.
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