Biomaterial Database

Effect of starvation on tRNA synthesis, amino acid pool, tRNA charging levels and aminoacyl-tRNA synthetase activities in the posterior silk gland of Bombyx mori L. 1979

G Chavancy, and A Fournier

Changes in the translational machinery components of the Bombyx mori posterior silk gland were analysed during starvation and refeeding and compared to the regularly fed larvae. During starvation, tRNA and ribosomal RNA synthesis are stopped. The amounts of different RNA classes and of the different tRNA species slow down at the same rate. Thus various tRNA show similar half-lifes and the preexisting tRNA adaptation to fibroin mRNA translation persists during starvation. Similarly, the tRNA/rRNA ratio is constant during starvation and refeeding (12 tRNA molecules for one ribosome) as in silk glands of control animals. Aminoacyl-tRNA synthetases and tRNA charging levels are decreased during starvation. The maximal tRNA charging level obtained during maximal protein synthesis in control animals is regained after 24 h refeeding of starved larvae. Changes observed in the free amino acid pool are not similar from one amino acid to another and levels reached after starvation do not differ strongly from the controls. Our results suggest that the production of translation apparatus components is coordinated and adjusted to the protein synthesis activity. Whether this coordination occurs in the silk gland is discussed on the basis of the "metabolic regulation", primarily described in prokaryotes and Yeast. Transfer RNA charging levels seem to play a key role in the process of regulation and could be implicated in the mechanism of tRNA adaptation if this phenomenon results as expected from a transcriptional control.

UI	MeSH Term	Description	Entries
D007814	Larva	Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.	Maggots,Tadpoles,Larvae,Maggot,Tadpole
D005088	Exocrine Glands	Glands of external secretion that release its secretions to the body's cavities, organs, or surface, through a duct.	Exocrine Gland,Gland, Exocrine,Glands, Exocrine
D006207	Half-Life	The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity.	Halflife,Half Life,Half-Lifes,Halflifes
D000596	Amino Acids	Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.	Amino Acid,Acid, Amino,Acids, Amino
D000604	Amino Acyl-tRNA Synthetases	A subclass of enzymes that aminoacylate AMINO ACID-SPECIFIC TRANSFER RNA with their corresponding AMINO ACIDS.	Amino Acyl T RNA Synthetases,Amino Acyl-tRNA Ligases,Aminoacyl Transfer RNA Synthetase,Aminoacyl-tRNA Synthetase,Transfer RNA Synthetase,tRNA Synthetase,Acyl-tRNA Ligases, Amino,Acyl-tRNA Synthetases, Amino,Amino Acyl tRNA Ligases,Amino Acyl tRNA Synthetases,Aminoacyl tRNA Synthetase,Ligases, Amino Acyl-tRNA,RNA Synthetase, Transfer,Synthetase, Aminoacyl-tRNA,Synthetase, Transfer RNA,Synthetase, tRNA,Synthetases, Amino Acyl-tRNA
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012343	RNA, Transfer	The small RNA molecules, 73-80 nucleotides long, that function during translation (TRANSLATION, GENETIC) to align AMINO ACIDS at the RIBOSOMES in a sequence determined by the mRNA (RNA, MESSENGER). There are about 30 different transfer RNAs. Each recognizes a specific CODON set on the mRNA through its own ANTICODON and as aminoacyl tRNAs (RNA, TRANSFER, AMINO ACYL), each carries a specific amino acid to the ribosome to add to the elongating peptide chains.	Suppressor Transfer RNA,Transfer RNA,tRNA,RNA, Transfer, Suppressor,Transfer RNA, Suppressor,RNA, Suppressor Transfer
D012831	Bombyx	A genus of silkworm MOTHS in the family Bombycidae of the order LEPIDOPTERA. The family contains a single species, Bombyx mori from the Greek for silkworm + mulberry tree (on which it feeds). A native of Asia, it is sometimes reared in this country. It has long been raised for its SILK and after centuries of domestication it probably does not exist in nature. It is used extensively in experimental GENETICS. (From Borror et al., An Introduction to the Study of Insects, 4th ed, p519)	Bombyx mori,Silkmoths,Silkworms,Silkmoth,Silkworm,Bombyx morus,Bombyxs,mori, Bombyx
D013217	Starvation	Lengthy and continuous deprivation of food. (Stedman, 25th ed)