Sensory modalities are essential for navigating through an ever-changing environment. From insects to mammals, transient receptor potential (TRP) channels are known mediators for cellular sensing. Chlamydomonas reinhardtii is a motile single-celled freshwater green alga that is guided by photosensory, mechanosensory, and chemosensory cues. In this type of alga, sensory input is first detected b...

The general consensus is that brain serotonin (5-HT) inhibits feed intake in teleost fishes and other vertebrates. Dietary manipulations with the 5-HT precursor tryptophan (TRP) have, however, yielded contradictory effects on feed intake, while studies of the endocrine response to stress indicate that the effects of TRP-enriched feed are context dependent. A characteristic behavioural response ...

The abilities of 14 tryptophan analogs to repress the tryptophan (trp) operon have been studied in Escherichia coli cells derepressed by incubation with 0.25 mM indole-3-propionic acid (IPA). trp operon expression was monitored by measuring the specific activities of anthranilate synthase (EC 4.1.3.27) and the tryptophan synthase (EC 4.2.1.20) beta subunit. Analogs characterized by modification...

Our long-term goal is the in vivo expression of intrinsically colored proteins without the need for further posttranslational modification or chemical functionalization by externally added reagents. Biocompatible (Aza)Indoles (Inds)/(Aza)Tryptophans (Trp) as optical probes represent almost ideal isosteric substitutes for natural Trp in cellular proteins. To overcome the limits of the traditiona...

Regulatory and functional aspects of the kynurenine (K) pathway (KP) of tryptophan (Trp) degradation are reviewed. The KP accounts for ~95% of dietary Trp degradation, of which 90% is attributed to the hepatic KP. During immune activation, the minor extrahepatic KP plays a more active role. The KP is rate-limited by its first enzyme, Trp 2,3-dioxygenase (TDO), in liver and indoleamine 2,3-dioxy...