scholarly journals Aminopeptidase I Is Targeted to the Vacuole by a Nonclassical Vesicular Mechanism

1997 ◽  
Vol 138 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Sidney V. Scott ◽  
Misuzu Baba ◽  
Yoshinori Ohsumi ◽  
Daniel J. Klionsky
Keyword(s):  
Mutant Strain ◽  
Subcellular Fractionation ◽  
Marker Proteins ◽  
In Vivo Analysis ◽  
Autophagy Pathway ◽  
Intermediate Compartment ◽  
Vacuolar Protein ◽  
Molecular Components

The yeast vacuolar protein aminopeptidase I (API) is synthesized as a cytosolic precursor that is transported to the vacuole by a nonclassical targeting mechanism. Recent genetic studies indicate that the biosynthetic pathway that transports API uses many of the same molecular components as the degradative autophagy pathway. This overlap coupled with both in vitro and in vivo analysis of API import suggested that, like autophagy, API transport is vesicular. Subcellular fractionation experiments demonstrate that API precursor (prAPI) initially enters a nonvacuolar cytosolic compartment. In addition, subvacuolar vesicles containing prAPI were purified from a mutant strain defective in breakdown of autophagosomes, further indicating that prAPI enters the vacuole inside a vesicle. The purified subvacuolar vesicles do not appear to contain vacuolar marker proteins. Immunogold EM confirms that prAPI is localized in cytosolic and in subvacuolar vesicles in a mutant strain defective in autophagic body degradation. These data suggest that cytosolic vesicles containing prAPI fuse with the vacuole to release a membrane-bounded intermediate compartment that is subsequently broken down, allowing API maturation.

scholarly journals Hexapod Assassins’ Potion: Venom Composition and Bioactivity from the Eurasian Assassin Bug Rhynocoris iracundus

Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 819
Author(s):  
Nicolai Rügen ◽  
Timothy P. Jenkins ◽  
Natalie Wielsch ◽  
Heiko Vogel ◽  
Benjamin-Florian Hempel ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Galleria Mellonella ◽  
Systemic Reactions ◽  
Venom Composition ◽  
Assassin Bug ◽  
Molecular Components ◽  
First Time ◽  
Tissue Digestion

Assassin bug venoms are potent and exert diverse biological functions, making them potential biomedical goldmines. Besides feeding functions on arthropods, assassin bugs also use their venom for defense purposes causing localized and systemic reactions in vertebrates. However, assassin bug venoms remain poorly characterized. We collected the venom from the assassin bug Rhynocoris iracundus and investigated its composition and bioactivity in vitro and in vivo. It caused lysis of murine neuroblastoma, hepatoma cells, and healthy murine myoblasts. We demonstrated, for the first time, that assassin bug venom induces neurolysis and suggest that it counteracts paralysis locally via the destruction of neural networks, contributing to tissue digestion. Furthermore, the venom caused paralysis and melanization of Galleria mellonella larvae and pupae, whilst also possessing specific antibacterial activity against Escherichia coli, but not Listeria grayi and Pseudomonas aeruginosa. A combinatorial proteo-transcriptomic approach was performed to identify potential toxins responsible for the observed effects. We identified neurotoxic Ptu1, an inhibitory cystin knot (ICK) toxin homologous to ω-conotoxins from cone snails, cytolytic redulysins homologous to trialysins from hematophagous kissing bugs, and pore-forming hemolysins. Additionally, chitinases and kininogens were found and may be responsible for insecticidal and cytolytic activities. We demonstrate the multifunctionality and complexity of assassin bug venom, which renders its molecular components interesting for potential biomedical applications.

scholarly journals Drosophila Hormone Receptor 38 Functions in Metamorphosis: A Role in Adult Cuticle Formation

Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1465-1475 ◽  
Author(s):  
T Kozlova ◽  
G V Pokholkova ◽  
G Tzertzinis ◽  
J D Sutherland ◽  
I F Zhimulev ◽  
...  
Keyword(s):  
Pupal Stage ◽  
Transcription Unit ◽  
P Element ◽  
Specific Response ◽  
Orphan Receptors ◽  
Mrna Isoforms ◽  
A Cell ◽  
In Vivo Analysis

Abstract DHR38 is a member of the steroid receptor superfamily in Drosophila homologous to the vertebrate NGFI-B-type orphan receptors. In addition to binding to specific response elements as a monomer, DHR38 interacts with the USP component of the ecdysone receptor complex in vitro, in yeast and in a cell line, suggesting that DHR38 might modulate ecdysone-triggered signals in the fly. We characterized the molecular structure and expression of the Dhr38 gene and initiated an in vivo analysis of its function(s) in development. The Dhr38 transcription unit spans more than 40 kb in length, includes four introns, and produces at least four mRNA isoforms differentially expressed in development; two of these are greatly enriched in the pupal stage and encode nested polypeptides. We characterized four alleles of Dhr38: a P-element enchancer trap line, l(2)02306, which shows exclusively epidermal staining in the late larval, pre-pupal and pupal stages, and three EMS-induced alleles. Dhr38 alleles cause localized fragility and rupturing of the adult cuticle, demonstrating that Dhr38 plays an important role in late stages of epidermal metamorphosis.

scholarly journals Marliolide Derivative Induces Melanosome Degradation via Nrf2/p62-Mediated Autophagy

2021 ◽  
Vol 22 (8) ◽  
pp. 3995
Author(s):  
Cheong-Yong Yun ◽  
Nahyun Choi ◽  
Jae Un Lee ◽  
Eun Jung Lee ◽  
Ji Young Kim ◽  
...  
Keyword(s):  
Related Factor ◽  
Melanin Pigmentation ◽  
Microtubule Associated Proteins ◽  
Melanocyte Stimulating Hormone ◽  
Associated Proteins ◽  
Autophagy Pathway ◽  
Nrf2 Activator ◽  
Promising Therapeutic Agent

Nuclear factor erythroid 2-related factor 2 (Nrf2), which is linked to autophagy regulation and melanogenesis regulation, is activated by marliolide. In this study, we investigated the effect of a marliolide derivative on melanosome degradation through the autophagy pathway. The effect of the marliolide derivative on melanosome degradation was investigated in α-melanocyte stimulating hormone (α-MSH)-treated melanocytes, melanosome-incorporated keratinocyte, and ultraviolet (UV)B-exposed HRM-2 mice (melanin-possessing hairless mice). The marliolide derivative, 5-methyl-3-tetradecylidene-dihydro-furan-2-one (DMF02), decreased melanin pigmentation by melanosome degradation in α-MSH-treated melanocytes and melanosome-incorporated keratinocytes, evidenced by premelanosome protein (PMEL) expression, but did not affect melanogenesis-associated proteins. The UVB-induced hyperpigmentation in HRM-2 mice was also reduced by a topical application of DMF02. DMF02 activated Nrf2 and induced autophagy in vivo, evidenced by decreased PMEL in microtubule-associated proteins 1A/1B light chain 3B (LC3)-II-expressed areas. DMF02 also induced melanosome degradation via autophagy in vitro, and DMF02-induced melanosome degradation was recovered by chloroquine (CQ), which is a lysosomal inhibitor. In addition, Nrf2 silencing by siRNA attenuated the DMF02-induced melanosome degradation via the suppression of p62. DMF02 induced melanosome degradation in melanocytes and keratinocytes by regulating autophagy via Nrf2-p62 activation. Therefore, Nrf2 activator could be a promising therapeutic agent for reducing hyperpigmentation.

scholarly journals The ER–Golgi intermediate compartment is a key membrane source for the LC3 lipidation step of autophagosome biogenesis

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Liang Ge ◽  
David Melville ◽  
Min Zhang ◽  
Randy Schekman
Keyword(s):  
Autophagosome Formation ◽  
Functional Studies ◽  
A Cell ◽  
Intermediate Compartment ◽  
Membrane Isolation ◽  
Necessary And Sufficient ◽  
Organelle Membrane ◽  
Catabolic Process

Autophagy is a catabolic process for bulk degradation of cytosolic materials mediated by double-membraned autophagosomes. The membrane determinant to initiate the formation of autophagosomes remains elusive. Here, we establish a cell-free assay based on LC3 lipidation to define the organelle membrane supporting early autophagosome formation. In vitro LC3 lipidation requires energy and is subject to regulation by the pathways modulating autophagy in vivo. We developed a systematic membrane isolation scheme to identify the endoplasmic reticulum–Golgi intermediate compartment (ERGIC) as a primary membrane source both necessary and sufficient to trigger LC3 lipidation in vitro. Functional studies demonstrate that the ERGIC is required for autophagosome biogenesis in vivo. Moreover, we find that the ERGIC acts by recruiting the early autophagosome marker ATG14, a critical step for the generation of preautophagosomal membranes.

scholarly journals In vitro and in vivo evaluation of diamond-coated strips

2016 ◽  
Vol 87 (3) ◽  
pp. 455-459 ◽  
Author(s):  
Roberta Lione ◽  
Francesca Gazzani ◽  
Chiara Pavoni ◽  
Stefano Guarino ◽  
Vincenzo Tagliaferri ◽  
...  
Keyword(s):  
Contact Point ◽  
Sem Analysis ◽  
Tribological Test ◽  
In Vivo Evaluation ◽  
Wear Performance ◽  
Abrasive Grains ◽  
Abrasive Power ◽  
In Vivo Analysis

ABSTRACT Objective: To test in vitro and in vivo the wear performance of diamond-coated strips by means of tribological testing and scanning electronic microscope (SEM). Materials and Methods: To evaluate the in vitro wear performance, a tribological test was performed by a standard tribometer. The abrasive strips slid against stationary, freshly extracted premolars fixed in resin blocks, at a 2-newton load. At the end of the tribological test, the residual surface of the strip was observed by means of SEM analysis, which was performed every 50 meters until reaching 300 meters. For the in vivo analysis, the strip was used for 300 seconds, corresponding to 250 meters. Results: The strips presented a fenestrated structure characterized by diamond granules alternating with voids. After the first 50 meters, it was possible to observe tooth material deposited on the surface of the strips and a certain number of abrasive grains detached. The surface of the strip after 250 meters appeared smoother and therefore less effective in its abrasive power. After 300 seconds of in vivo utilization of the strip, it was possible to observe the detachment of diamond abrasive grains, the near absence of the grains and, therefore, loss of abrasive power. Conclusions: Under ideal conditions, after 5 minutes (300 meters) of use, the strip loses its abrasive capacity by about 60%. In vivo, a more rapid loss of abrasive power was observed due to the greater load applied by the clinician in forcing the strip into the contact point.

The control of trophoblastic growth in the guinea pig

Development ◽  
1980 ◽  
Vol 60 (1) ◽  
pp. 405-418
Author(s):  
E. B. Ilgren
Keyword(s):  
Guinea Pig ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
The Other ◽  
In Vivo Analysis

The growth of mouse trophectoderm depends upon the presence of the inner cell mass. Whether this applies to other species of mammals is not known. To investigate this problem, the guinea pig was selected for two reasons. Firstly, the growth of guinea-pig trophoblast resembles that of man. Secondly, earlier studies suggest that the proliferation of guinea-pig trophectoderm may not be under ICM control. Therefore, in the present study, the guinea-pig blastocyst was cut microsurgically to yield two tissue fragments. These contained roughly equal numbers of trophectodermal cells, one fragment being composed only of trophectoderm and the other containing ICM tissue as well. Subsequently, the growth of these mural and polar fragments was followed in vitro since numerous technical difficulties make an in vivo analysis of this problem impracticable. In a manner similar to the mouse, the isolated mural trophectoderm of the guinea pig stopped dividing and became giant. In contrast, guinea-pig polar fragments formed egg-cylinder-like structures. The latter contained regions structurally similar to two presumptive polar trophectodermal derivatives namely the ectoplacental and extraembryonic ectodermal tissues. These findings suggest that guinea-pig trophectodermal growth may occur in a manner similar to the mouse and thus be under ICM control.

scholarly journals Structure Based Design and Synthesis of Peptide Inhibitor of Human LOX-12: In Vitro and In Vivo Analysis of a Novel Therapeutic Agent for Breast Cancer

PLoS ONE ◽  
2012 ◽  
Vol 7 (2) ◽  
pp. e32521 ◽  
Author(s):  
Abhay kumar Singh ◽  
Ratnakar Singh ◽  
Farhat Naz ◽  
Shyam Singh Chauhan ◽  
Amit Dinda ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Therapeutic Agent ◽  
Peptide Inhibitor ◽  
Design And Synthesis ◽  
In Vivo Analysis ◽  
Novel Therapeutic
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