The heteropolymeric O-antigen of the lipopolysaccharide from Pseudomonas aeruginosa serogroup O5 as well as the band-A trisaccharide from Bordetella pertussis contain the di-N-acetylated mannosaminuronic acid derivative, beta-D-ManNAc3NAcA (2,3-diacetamido-2,3-dideoxy-beta-D-mannuronic acid). The biosynthesis of the precursor for this sugar is proposed to require five steps, through which UDP-a...

This perspective paper focuses on the most recent results suggesting a potential role for UDP-Glucose as a signaling molecule in plants. In animals, UDP-Glucose is well-established as an extracellular signaling molecule that is sensed by G-protein coupled receptors, activating several downstream defense mechanisms. Recent studies have shown that abnormal growth occurred in both vegetative and r...

Inherent vulnerability of the wireless medium renders it more susceptible to errors and losses than classical wired media. In this paper, we evaluate the suitability of protocols and strategies across different layers of the stack to provide real-time services over 802.11b wireless LANs. More specifically, within the context of cross-layer design, we compare the performance of UDP with UDP Lite...

We introduce UDP Lite – a lightweight version of UDP with increased flexibility in the form of a partial checksum. It allows senders to specify packets as partially insensitive to errors. The coverage of the checksum is specified by the sending application on a per-packet basis. Because of its close relationship to UDP, UDP Lite is easily integrated into an existing UDP implementation. UDP is a...

The P2Y14 receptor was initially identified as a G protein-coupled receptor activated by UDP-glucose and other nucleotide sugars. We have developed several cell lines that stably express the human P2Y14 receptor, allowing facile examination of its coupling to native Gi family G proteins and their associated downstream signaling pathways (J Pharmacol Exp Ther 330:162-168, 2009). In the current s...

An improved understanding of the biological activities of heparin requires structurally defined heparin oligosaccharides. The chemoenzymatic synthesis of heparin oligosaccharides relies on glycosyltransferases that use UDP-sugar nucleotides as donors. Uridine 5'-diphosphoiduronic acid (UDP-IdoA) and uridine 5'-diphosphohexenuronic acid (UDP-HexUA) have been synthesized as potential analogues of...

Plants utilize UDP-arabinofuranose (UDP-Araf) in the biosynthesis of Araf-containing complex carbohydrates. UDP-Araf is synthesized from UDP-arabinopyranose by UDP-arabinopyranose mutases (UAMs). Here we describe the heterologous expression of rice (Oryza sativa) UAM genes in insect cells and report some of their enzymatic properties. Recombinant UAMs might serve as useful tools for the biosynt...

Firewall support for UDP traffic today is still insecure and inadequate. We propose in this paper a Transport Layer Proxy (TLP) to provide a secure UDP firewall traversal service on the transport layer (the TLP supports TCP as well). For each UDP association with endpoints separated by a TLP server, the TLP server performs userlevel or host-level authentication, packet filtering, packet relayin...

Hepatic microsomal UDP-glucuronosyltransferases towards androsterone and testosterone were purified by chromatofocusing and UDP-hexanolamine affinity chromatograpy in Wistar rats which had genetic deficiency of androsterone UDP-glucuronosyltransferase activity. In rats with the high-activity phenotype, androsterone (the 3-hydroxy androgen) UDP-glucuronosyltransferase was eluted at about pH 7.4 ...

Efficient management of fertilizers and irrigation could mitigate greenhouse gas (GHG) emissions increase crop yields. Field experiments were conducted to determine the effects an integrated plant nutrient system (IPNS) water regime—alternate wetting drying (AWD) continuous flooding (CF)—on GHG rice yield. Fertilizer treatments included control (no N), prilled urea (PU), deep placement (UDP), I...