## Abstract Like many euryhaline marine invertebrates, the copepod __Tigriopus californicus__ acclimates to changes in environmental salinity by adjusting intracellular concentrations of free amino acids (FAA). Proline and alanine are the primary contributors to the FAA pool, and previous work has
Regulation of proline synthesis during osmotic stress in the copepodTigriopus californicus
✍ Scribed by Burton, Ronald S.
- Publisher
- John Wiley and Sons
- Year
- 1991
- Tongue
- English
- Weight
- 727 KB
- Volume
- 259
- Category
- Article
- ISSN
- 0022-104X
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
The marine copepod Tigriopus californicus shows rapid adjustment of intracellular proline and alanine pools in response to salinity stress. Small increases in salinity (on the order of 2 ppt or 50 mOsmoles) are sufficient to elicit proline synthesis in animals acclimated to 50% seawater. Increases in osmolarity achieved by adding organic solutes to a 50% seawater medium also elicited proline (but not alanine) synthesis. In constant 50% seawater, label from ^14^C‐(U)‐glucose is incorporated into the free alanine and glutamate (but not proline) pools; only the proline pool shows a monotonic increase in specific activity following transfer to 100% seawater. To demonstrate that glutamate is a proline precursor, ^14^C‐(U)‐glutamate was provided to animals maintained in 50% seawater (control) and animals transferred to 100% seawater; salinity change resulted in the rapid increase in alanine and proline concentrations, with proline (and not alanine) achieving specific activities similar to that of the glutamate pool. Taken together, these results indicate that small hyperosmotic stimuli result in the induction of proline synthesis from glutamate. The regulation of proline synthesis involves mechanisms discrete from those regulating the concentrations of other FAA functioning in osmotic response.
📜 SIMILAR VOLUMES
## Abstract Spontaneously occurring thallium‐resistant (Tl^+^‐R) mutant of diazotrophic, heterocystous cyanobacterium __Nostoc muscorum__ is described in which Tl^+^‐R phenotype is the cause of defective salinity‐inducible K^+^ uptake activity and proline uptake activity. The results indicate that
Plasmodium falciparum antigens as target molecules for a protective immunization against malaria: an up-to-date review. Z. Parasitenk. 72, 1-1 I .
## Abstract The wood frog (__Rana sylvatica__) exhibits a well‐developed natural anoxia and dehydration tolerance. The degree of stress tolerance depends on numerous biochemical adaptations, including stress‐induced hypometabolism that helps to preserve long‐term viability by reducing ATP demand. W
## Abstract Cyclic mechanical stress (CMS) leads to alterations of cellular functions in the trabecular meshwork (TM), including the up‐regulation of transforming growth factor beta 1 (TGFβ1), that can potentially contribute to the pathogenesis of glaucoma. Although microRNAs (miRNAs) are known to
## Abstract Iron deficiency causes oversynthesis of riboflavin in several yeast species, known as flavinogenic yeasts. However, the mechanisms of such regulation are not known. We found that mutations causing riboflavin overproduction and iron hyperaccumulation (__rib80, rib81__ and __hit1__), as w