No abstract available.
Animals ; Female ; Ovary* ; Rats* ; Serine Proteases* ; Serine*

Kunitz-type serine protease inhibitors are a class of ubiquitous protease inhibitors, which play important roles in various life activities. The structures of such inhibitors are generally stable, and are usually characterized by the presence of one or several Kunitz domains in tandem, which are able to bind to serine proteases in a manner similar to substrate binding, thereby inhibiting enzyme activity. In terms of function, Kunitz-type serine protease inhibitors are involved in processes such as blood coagulation and fibrinolysis, tumor immunity, inflammation regulation, and resistance to bacterial and fungal infections. This article summarizes the advances of Kunitz-type serine protease inhibitors and provides new ideas for the development of novel Kunitz-type serine protease inhibitors.
Protease Inhibitors ; Serine Proteases ; Serine Proteinase Inhibitors

No abstract available.
Humans* ; Keratinocytes* ; Protein-Serine-Threonine Kinases* ; Serine* ; Threonine*

Humans ; Phosphorylation ; Serine ; Protein Serine-Threonine Kinases/metabolism* ; Spasms, Infantile

Animals ; Atherosclerosis ; Humans ; Serine Proteinase Inhibitors ; Serpins

L-Homoserine is a non-essential amino acid that is often used as an important platform compound and additive in industrial production. To improve the production efficiency, a previously constructed L-homoserine producing strain E. coli H0-0 was used as a chassis for further metabolic modification. Firstly, the ppc and pyccgP458S genes were overexpressed to optimize the Kreb's cycle. Subsequently, thrAC1034T and lysCcgC932T were overexpressed to improve the product synthesis, followed by inactivation of iclR gene to reduce the accumulation of by-products. The introduction of three sucrose metabolism genes, scrA, scrB and scrK, enabled E. coli to ferment sucrose. The titer of L-homoserine increased from 3.2 g/L to 11.1 g/L.
Escherichia coli/genetics* ; Homoserine ; Metabolic Engineering ; Serine

Humans ; Phosphorylation ; Serine/metabolism* ; Protein Serine-Threonine Kinases/metabolism* ; Signal Transduction ; Neovascularization, Pathologic

In several human tumors, signal transducer and activator of transcription 3 (STAT3) and nuclear factor κB (NFκB) are activated and interact; how these STAT3–NFκB complexes are transported to the nucleus is not fully understood. In this study, we found that Rac1 was activated in starved cancer cells and that activated Rac1 coexisted with STAT3 and NFκB. Rac1 knockdown and overexpression of the dominant-negative mutant Rac1N19 inhibited the degradation of IκBα, an inhibitor of NFκB. MG132, an inhibitor of the ubiquitin proteasome pathway, increased the amount of non-phosphorylated IκBα, but not serine-phosphorylated IκBα, indicating that IκBα degradation by Rac1 in starved cancer cells is independent of IκBα serine phosphorylation by IKK. Rac1 knockdown also inhibited the nuclear translocation of STAT3–NFκB complexes, indicating that this translocation requires activated Rac1. We also demonstrated that the mutant STAT3 Y705F could form complexes with NFκB, and these unphosphorylated STAT3–NFκB complexes translocated into the nucleus and upregulated the activity of NFκB in starved cancer cells, suggesting that phosphorylation of STAT3 is not essential for its translocation. To our knowledge, this is the first study demonstrating the crucial role of Rac1 in the function of STAT3–NFκB complexes in starved cancer cells and implies that targeting Rac1 may have future therapeutic significance in cancer therapy.
Humans ; Phosphorylation ; Proteasome Endopeptidase Complex ; Serine ; STAT3 Transcription Factor ; Ubiquitin

We investigated the combined moisturizing effect of liposomal serine and a cosmeceutical base selected in this study. Serine is a major amino acid consisting of natural moisturizing factors and keratin, and the hydroxyl group of serine can actively interact with water molecules. Therefore, we hypothesized that serine efficiently delivered to the stratum corneum (SC) of the skin would enhance the moisturizing capability of the skin. We prepared four different cosmeceutical bases (hydrogel, oil-in-water (O/W) essence, O/W cream, and water-in-oil (W/O) cream); their moisturizing abilities were then assessed using a Corneometer(R). The hydrogel was selected as the optimum base for skin moisturization based on the area under the moisture content change-time curves (AUMCC) values used as a parameter for the water hold capacity of the skin. Liposomal serine prepared by a reverse-phase evaporation method was then incorporated in the hydrogel. The liposomal serine-incorporated hydrogel (serine level=1%) showed an approximately 1.62~1.77 times greater moisturizing effect on the skin than those of hydrogel, hydrogel with serine (1%), and hydrogel with blank liposome. However, the AUMCC values were not dependent on the level of serine in liposomal serine-loaded hydrogels. Together, the delivery of serine to the SC of the skin is a promising strategy for moisturizing the skin. This study is expected to be an important step in developing highly effective moisturizing cosmeceutical products.
Hyaluronic Acid* ; Hydrogel* ; Hydrogels* ; Liposomes ; Serine* ; Skin* ; Water

Translationally controlled tumor proteins (TCTP) and SNF1- related protein kinase (SnRK1) are conserved and widely present in eukaryotic cells. TCTP regulates cell division, plant growth and development, and mediates plant resistance against pathogen infection. SnRK1 participates in a range of physiological processes including sugar metabolism and resistance to abiotic and biotic stresses. Previous work in our laboratory demonstrated that wheat TCTP can respond to Puccinia triticina infection and induce host defense responses. In order to further investigate the mechanism of TaTCTP in wheat resistance to Puccinia triticina infection, we used TAP (tandem affinity purification) and mass spectrometry to screen the potential interactants of TaTCTP. A SNF1- related protein kinase (SnRK1) was identified as a potential interacting protein of TaTCTP. The results of yeast two-hybrid assay showed that TCTP could interact with SnRK1 in yeast, and the yeast carrying TCTP and SnRK1 could grow on SD/-Leu/-Trp/-His/-Ade (SD/-LWHA) medium. The fluorescence signal of the interaction between TCTP and SnRK1 was found to be distributed in the cytoplasm in the Bi-fluorescense complementation experiment. Co-IP experiments further showed that TCTP and SnRK1 could interact in plant cells. This study lays an important foundation for further studying the mechanism of TaTCTP in the interaction between wheat and Puccinia triticina, and it play a great influence on further improving the molecular mechanism of wheat resistant to Puccinia triticina.
Basidiomycota ; Humans ; Neoplasms ; Protein Biosynthesis ; Protein-Serine-Threonine Kinases ; Triticum