Search results for "sperm"

Molecular mechanism of T-cell protein tyrosine phosphatase (TCPTP) activation by mitoxantrone.

2013

T-cell protein tyrosine phosphatase (TCPTP) is a ubiquitously expressed non-receptor protein tyrosine phosphatase. It is involved in the negative regulation of many cellular signaling pathways. Thus, activation of TCPTP could have important therapeutic applications in diseases such as cancer and inflammation. We have previously shown that the α-cytoplasmic tail of integrin α1β1 directly binds and activates TCPTP. In addition, we have identified in a large-scale high-throughput screen six small molecules that activate TCPTP. These small molecule activators include mitoxantrone and spermidine. In this study, we have investigated the molecular mechanism behind agonist-induced TCPTP activation.…

Influence of agents that act on DNA and RNA synthesis on the activity of poly(ADP-Rib) polymerase

1975

The activity of poly(ADP-Rib) polymerase is enhanced in the presence of spermine and spermidine. Among the adenosine-like antibiotics tested, only formycin B and showdomycin cause an inhibition of the enzyme, which is competitive to NAD. The activity of poly(ADP-Rib) polymerase is not reduced by rifamycin, alpha-amanitin and 2-phenylethanol.

Terpenoid glycosides from the root's barks of Eriocoelum microspermum Radlk. ex Engl.

2018

Abstract Eight undescribed triterpenoid saponins together with a known one, and two undescribed sesquiterpene glycosides were isolated from root's barks of Eriocoelum microspermum. Their structures were elucidated by spectroscopic methods including 1D and 2D experiments in combinaison with mass spectrometry as 3-O-α-L-rhamnopyranosyl-(1 → 3)-[α-L-rhamnopyranosyl-(1 → 2)]-α-L-arabinopyranosylhederagenin, 3-O-α-L-rhamnopyranosyl-(1 → 3)-[β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)]-α-L-arabinopyranosylhederagenin, 3-O-α-L-rhamnopyranosyl-(1 → 3)-[β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)]-α-L-arabinopyranosylhederagenin, 3-O-α-L-rhamnopyranosyl-(1 → 4)-[α-L-rhamnopyrano…

Sperm imprinting integrity in seminoma patients?

2018

IF 4.990; International audience; BackgroundTesticular germ cell tumor such as seminoma is strongly associated with male reproductive problems commonly associated with the alteration of sperm parameters as described in testicular dysgenesis syndrome. Interestingly, numerous studies have reported that the precursor of germ cell cancer, germ cell neoplasia in situ (GCNIS), present similarities to fetal gonocytes, specifically characterized by global DNA hypomethylation particularly on imprinting sequences. These disorders may have a common origin derived from perturbations of embryonal programming during fetal development. Presently, there is no available information concerning the sperm DNA …

Rapid Self-Healing and Thixotropic Organogelation of Amphiphilic Oleanolic Acid–Spermine Conjugates

2021

Natural and abundant plant triterpenoids are attractive starting materials for the synthesis of conformationally rigid and chiral building blocks for functional soft materials. Here, we report the rational design of three oleanolic acid-triazole-spermine conjugates, containing either one or two spermine units in the target molecules, using the Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition reaction. The resulting amphiphile-like molecules 2 and 3, bearing just one spermine unit in the respective molecules, self-assemble into highly entangled fibrous networks leading to gelation at a concentration as low as 0.5% in alcoholic solvents. Using step-strain rheological measurements, we show ra…

Perturbation of spermine synthase Gene Expression and Transcript Profiling Provide New Insights on the Role of the Tetraamine Spermine in Arabidopsis…

2011

The role of the tetraamine spermine in plant defense against pathogens was investigated by using the Arabidopsis (Arabidopsis thaliana)-Pseudomonas viridiflava pathosystem. The effects of perturbations of plant spermine levels on susceptibility to bacterial infection were evaluated in transgenic plants (35S::spermine synthase [SPMS]) that overexpressed the SPMS gene and accumulated spermine, as well as in spms mutants with low spermine levels. The former exhibited higher resistance to P. viridiflava than wild-type plants, while the latter were more susceptible. Exogenous supply of spermine to wild-type plants also increased disease resistance. Increased resistance provided by spermine was p…

Alkaloids from Cell Cultures of Aspidosperma Quebracho-Blanco

1995

Baltijas jūras reģiona endēmo augu sugu Tragopogon heterospermus un Anthyllis maritima populāciju ekoloģija Latvijā

2015

Viena no Baltijas jūras reģiona aktualitātēm ir endēmo augu sugu, to dzīvotņu saglabāšana. Pētījums veikts ar mērķi noteikt nozīmīgākos Tragopogon heterospermus un Anthyllis maritima populāciju ietekmējošos faktorus Latvijā. Darbā analizēti 2014. gadā ievāktie veģetācijas, augsnes un mikorizu dati Užavas un Pāvilostas apkārtnē. Ar NMDS ordināciju un GLM modeļu analīzi noteikti galvenie endēmo sugu ietekmējošie faktori. Piekrastes monitoringa dati (1994. - 2013. g.) izmantoti, lai raksturotu sugām tipiskās sabiedrības. Tie grupēti ar TWINSPAN metodi. Galvenie rezultāti rāda, ka, lai arī abas sugas ir tipiskas priekškāpu un pelēko kāpu augu sabiedrībās, A. maritima dzīvotnēm raksturīgas arī a…

A major cysteine proteinase, EPB, in germinating barley seeds: structure of two intronless genes and regulation of expression

1996

The barley cysteine proteinase B (EPB) is the main protease responsible for the degradation of endosperm storage proteins providing nitrogenous nutrients to support the growth of young seedlings. The expression of this enzyme is induced in the germinating seeds by the phytohormone, gibberellin, and suppressed by another phytohormone, abscisic acid. In situ hybridization experiments indicate that EPB is expressed in the scutellar epithelium within 24 h of seed germination, but the aleurone tissue surrounding the starchy endosperm eventually becomes the main tissue expressing this enzyme. The EPB gene family of barley consists of two very similar genes, EPB1 and EPB2, both of which have been …

The Norway spruce genome sequence and conifer genome evolution

2013

Conifers have dominated forests for more than 200 million years and are of huge ecological and economic importance. Here we present the draft assembly of the 20-gigabase genome of Norway spruce (Picea abies), the first available for any gymnosperm. The number of well-supported genes (28,354) is similar to the >100 times smaller genome of Arabidopsis thaliana, and there is no evidence of a recent whole-genome duplication in the gymnosperm lineage. Instead, the large genome size seems to result from the slow and steady accumulation of a diverse set of long-terminal repeat transposable elements, possibly owing to the lack of an efficient elimination mechanism. Comparative sequencing of Pinu…