SNAT

Platelets have been reported to exert diverse actions besides hemostasis and thrombus formation in the body. However, whether platelets affect transporter activity remains to be determined. In this study, we examined the effects of platelets on the activity of amino acid transporter system A, which is known to be changed by various factors, and we clarified the mechanism by which platelets affect system A activity. Among system A subtypes, we found that sodium-coupled neutral amino acid transporter (SNAT) 4 played a central role in the transport activity of system A in HuH-7 human hepatoma cells...

This study provides novel insights into the evolution, diversification, and functions of melatonin biosynthesis genes in Prunus species, highlighting their potential role in regulating bud dormancy and abiotic stresses. The biosynthesis of melatonin (MEL) in plants is primarily governed by enzymatic reactions involving key enzymes such as serotonin N-acetyltransferase (SNAT), tryptamine 5-hydroxylase (T5H), N-acetylserotonin methyltransferase (ASMT) and tryptophan decarboxylase (TDC). In this study, we analyzed Melatonin genes in four Prunus species such as Prunus avium (Pavi), Prunus pusilliflora (Ppus), Prunus serulata (Pser), and Prunus persica (Pper) based on comparative genomics approach...

Melatonin is a naturally occurring biologically active amine produced by plants, animals and microbes. This review explores the biosynthesis of melatonin in plants, with a particular focus on its diverse roles in Arabidopsis thaliana, a model species. Melatonin affects abiotic and biotic stress resistance in A. thaliana. Exogenous and endogenous melatonin is addressed in association with various conditions, including cold stress, high light stress, intense heat and infection with Botrytis cinerea or Pseudomonas, as well as in seed germination and lateral root formation...

The study on melatonin biosynthesis mutant snat1snat2 revealed that endogenous melatonin plays an important role in salt responsiveness by mediating auxin signaling. Melatonin is a pleiotropic signaling molecule, which, besides being involved in multiple growth and developmental processes, also mediates environmental stress responses. However, whether and how endogenous melatonin is involved in salt response has not been determined. In this study, we elucidated the involvement of endogenous melatonin in salt response by investigatiing the impact of salt stress on a double mutant of Arabidopsis (snat1snat2) defective in melatonin biosynthesis genes SNAT1 and SNAT2...

Immune-pineal axis activation is part of the assembly of immune responses. Proinflammatory cytokines inhibit the pineal synthesis of melatonin while inducing it in macrophages by mechanisms dependent on nuclear factor-κB (NF-κB) activation. Cytokines activating the Janus kinase/signal transducer and activator of transcription (STAT) pathways, such as interferon-gamma (IFN-γ) and interleukin-10 (IL-10), modulate melatonin synthesis in the pineal, bone marrow (BM), and spleen. The stimulatory effect of IFN-γ upon the pineal gland depends on STAT1/NF-κB interaction, but the mechanisms controlling IL-10 effects on melatonin synthesis remain unclear...

OBJECTIVE: We aimed to identify social needs of gynecologic oncology patients using a self-administered social needs assessment tool (SNAT), compare the SNAT to a formal social work assessment performed by cancer care navigators (CCN), and provide SNAT-informed community resources. METHODS: We analyzed prospectively collected data from a performance improvement initiative in a safety-net gynecologic oncology clinic between October 2021 and July 2022. We screened for eight social needs domains, health literacy, desire for social work, and presence of urgent needs...

Serotonin N -acetyltransferase (SNAT) functions as the penultimate or final enzyme in melatonin biosynthesis, depending on the substrate. The Escherichia coli orthologue of archaeal SNAT from Thermoplasma volcanium was identified as RimI (EcRimI), with 42% amino acid similarity to archaeal SNAT. EcRimI has been reported to be an N -acetyltransferase enzyme. Here, we investigated whether EcRimI also exhibits SNAT enzyme activity. To achieve this goal, we purified recombinant EcRimI and examined its SNAT enzyme kinetics...

A multiloop splitter-based non-cryogenic artificial trapping (M-SNAT) modulation technique was established, which applied the first (1 D) nonpolar and the second (2 D) polar columns, deactivated fused silica (DFS) columns, a microfluidic Deans switch (DS), and splitters located between the 1 D column outlet and the DS. The splitters were connected into multiple loops with a progressively doubled perimeter of the next loop. This enabled a duplex splitting mechanism within each loop consisting of splitting of analyte pulses, the pulse delay, and their combination which led to equally split peaks of the same analytes with the number of split peaks ( n split ) equal to 2 m ( m = number of loops)...

Due to the importance of joint disease and ostearthritis (OA) in equine athletes, new regenerative treatments to improve articular cartilage repair after damage are gaining relevance. Chondrocyte de-differentiation, an important pathogenetic mechanism in OA, is a limiting factor when differentiated articular chondrocytes are used for cell-based therapies. Current research focuses on the prevention of this de-differentiation and/or on the re-differentiation of chondrocytes by employing different strategies in vitro and in vivo...

Phytomelatonin is a pleiotropic signaling molecule that regulates plant growth, development, and stress response. In plant cells, phytomelatonin is synthesized from tryptophan via several consecutive steps that are catalyzed by tryptophan decarboxylase (TDC), tryptamine 5-hydroxylase (T5H), serotonin N -acyltransferase (SNAT), and N -acetylserotonin methyltransferase (ASMT) and/or caffeic acid-3- O -methyltransferase (COMT). Recently, the identification of the phytomelatonin receptor PMTR1 in Arabidopsis has been considered a turning point in plant research, with the function and signal of phytomelatonin emerging as a receptor-based regulatory strategy...

Serotonin N-acetyltransferase (SNAT) catalyzes the biosynthesis of N-acetylserotonin (NAS) and N-acetyltryptamine (NAT), two pleiotropic molecules with neurotransmitter functions. Here, we report the identification of a SNAT protein in the genus Staphylococcus . The SNAT gene identified in Staphylococcus pseudintermedius ED99, namely SPSE_0802 , encodes a 140 residues-long cytoplasmic protein. The recombinant protein SPSE_0802 was expressed in E. coli BL21 and found to acetylate serotonin (SER) and tryptamine (TRY) as well as other trace amines in vitro ...

A new clade of serotonin N -acetyltransferase (SNAT), the penultimate enzyme in the melatonin biosynthetic pathway, has been reported in the archaeon Thermoplasma volcanium . The closest homolog of archaea SNAT in human was an N -alpha-acetyltransferase50 (Naa50). To determine whether human Naa50 (hNaa50) shows SNAT enzyme activity, we chemically synthesized and expressed the hNaa50 gene in Escherichia coli , followed by Ni2+ affinity purification. Purified recombinant hNaa50 showed SNAT activity ( K m and V max values of 986 μM and 1800 pmol/min/mg protein, respectively)...

Rice bacterial blight (BB), caused by Xanthomonas oryzae pv. oryzae ( Xoo ), is one of the top ten bacterial plant diseases worldwide. Serotonin N -acetyltransferase (SNAT) is one of the key rate-limiting enzymes in melatonin (MT) biosynthesis. However, its function in pathogenic bacteria remains unclear. In this study, a Xoo SNAT protein (xoSNAT3) that showed 27.39% homology with sheep SNAT was identified from a collection of 24 members of GCN5-related N -acetyltransferase (GNAT) superfamily in Xoo . This xoSNAT3 could be induced by MT...

Membrane transporters are the key determinants of the homeostasis of endogenous compounds in the cells and their exposure to drugs. However, the substrate specificities of distinct transporters can overlap. In the present study, the interactions of l-type amino acid transporter 1 (LAT1)-utilizing prodrugs with sodium-coupled neutral amino acid transporter 2 (SNAT2) were explored. The results showed that the cellular uptake of LAT1-utilizing prodrugs into a human breast cancer cell line, MCF-7 cells, was mediated via SNATs as the uptake was increased at higher pH (8...

The plant St. John's wort contains high levels of melatonin, an important biochemical that has both beneficial and adverse effects on stress. Therefore, a method for increasing melatonin levels in plants without adversely affecting their growth is economically important. In this study, we investigated the regulation of melatonin levels in St. John's wort by exposing samples to salinity stress (150 mM) and salicylic acid (0.25 mM) to augment stress tolerance. The results indicated that salinity stress significantly reduced the plant chlorophyll content and damaged the photosystem, plant growth and development...

Fine-tuned interactions between melatonin (MT) and hormones affected by environmental inputs are crucial for plant growth. Under high light (HL) conditions, melatonin reduced photodamage in Arabidopsis thaliana and contributed to the restoration of the expression of the cytokinin (CK) synthesis genes IPT3 , IPT5 and LOG7 and genes for CK signal transduction AHK2 , 3 and ARR 1 , 4 , 5 and 12 which were downregulated by stress. However, CK signaling mutants displayed no significant changes in the expression of CK genes following HL + MT treatment, implying that a fully functional cytokinin signaling pathway is a prerequisite for MT-CK interactions...

Intrauterine growth restriction (IUGR), predominantly caused by placental insufficiency, affects partitioning of nutrients to the fetus. The system A sodium-coupled transporters (SNAT or SLC38), of types A1, A2, and A4, control non-essential amino acid uptake and supply. Here, we aimed to investigate the expression of these transporters across different placental disease cohorts and cells. To determine disease impact, transporter expressions at the gene (qPCR) and protein (western blots) level were assessed in gestationally matched placental tissues...

The effect of melatonin treatment on the carotenoid metabolism in broccoli florets during storage was explored. The results indicated that 100 µmol/L of melatonin maintained the sensory quality of broccoli florets, which retarded the increase of the L* value and the decrease of the H value. Melatonin treatment increased the activities of tryptophan decarboxylase (TDC), tryptamine 5-hydroxylase (T5H), serotonin N-acetyltransferase (SNAT) and N-acetylserotonin methyltransferase (ASMT), leading to the enrichment of endogenous melatonin content in broccoli florets...

Melatonin (Mel) is a multifunctional biomolecule found in both animals and plants. In plants the biosynthesis of Mel from tryptophan has been delineated to comprise of four consecutive reactions. However, whilst the genes encoding these enzymes in rice are well characterized no systematic evaluation of the overall pathway has, as yet, been published for wheat. In the current study, the relative contents of six Mel-pathway-intermediates including tryptophan (Trp), tryptamine (Trm), serotonin (Ser), 5-methoxy tryptamine (5M-Trm), N-acetyl serotonin (NAS) and Mel, were determined in 24 independent tissues spanning the lifetime of wheat...

To explore whether there is an interaction between melatonin (MT) and calcium (Ca2+ ) in regulating heat tolerance of plants, we analyzed the response of endogenous MT and Ca2+ to heat stress, and examined the effect of MT and Ca2+ on the reactive oxygen (ROS) accumulation, antioxidant system, and transcripts of heat shock factor ( HSF ) and heat shock proteins ( HSPs ) of cucumber seedlings under high temperature stress. Seedlings were foliar sprayed with 100 μmol·L-1 MT, 10 mmol·L-1 CaCl2 , 3 mmol·L-1 ethylene glycol tetraacetic acid (EGTA, Ca2+ chelating agent) +100 μmol·L-1 MT, 0...