Biomaterial Database

Differential subcellular distribution of guanine nucleotide exchange factor in suckling and adult rat brain. 1988

C Calés, and J L Fando, and A Alcazar, and M Salinas

Departamento de Investigación, Hospital Ramón y Cajal, Madrid, Spain.

Guanine nucleotide exchange factor (GEF) activity in ribosomal high salt wash and cytosolic fractions from suckling (4-10-day-old) and adult (60-day-old) rats was assayed by two different methods, by measuring: (i) its ability to promote binding of [3H]Met-tRNAi to eukaryotic initiation factor-2 (eIF-2) preparations that are partially or wholly in the form of eIF-2-GDP complexes (at Mg2+ concentrations near the optimum for protein synthesis), and (ii) under similar conditions, its ability to catalyze the displacement of [3H]GDP, previously bound to eIF-2, by unlabelled GDP. A purified eIF-2 (GEF-free) from brain was used as the source of eIF-2 activity. GEF activity in ribosomal fractions is higher in the brain of suckling than adults rats, and a direct correlation therefore exists between ribosomal GEF activity and the previously observed age-related decrease in eIF-2 activity in ribosomal high salt wash protein fractions. On the other hand GEF activity in the postmicrosomal supernatant is lower in the brain of suckling than adult rats. These findings further support the hypothesis that the progressive decrease in protein synthesis during brain development is controlled through regulation of the initiation step, by modulation of eIF-2/GEF activities.

UI	MeSH Term	Description	Entries
D010448	Peptide Initiation Factors	Protein factors uniquely required during the initiation phase of protein synthesis in GENETIC TRANSLATION.	Initiation Factors,Initiation Factor,Factors, Peptide Initiation,Initiation Factors, Peptide
D011506	Proteins	Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.	Gene Products, Protein,Gene Proteins,Protein,Protein Gene Products,Proteins, Gene
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D006153	Guanosine Diphosphate	A guanine nucleotide containing two phosphate groups esterified to the sugar moiety.	GDP,Guanosine 5'-Diphosphate,Guanosine 5'-Trihydrogen Diphosphate,5'-Diphosphate, Guanosine,5'-Trihydrogen Diphosphate, Guanosine,Diphosphate, Guanosine,Diphosphate, Guanosine 5'-Trihydrogen,Guanosine 5' Diphosphate,Guanosine 5' Trihydrogen Diphosphate
D000375	Aging	The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.	Senescence,Aging, Biological,Biological Aging
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
D012270	Ribosomes	Multicomponent ribonucleoprotein structures found in the CYTOPLASM of all cells, and in MITOCHONDRIA, and PLASTIDS. They function in PROTEIN BIOSYNTHESIS via GENETIC TRANSLATION.	Ribosome
D012346	RNA, Transfer, Amino Acyl	Intermediates in protein biosynthesis. The compounds are formed from amino acids, ATP and transfer RNA, a reaction catalyzed by aminoacyl tRNA synthetase. They are key compounds in the genetic translation process.	Amino Acyl tRNA,Transfer RNA, Amino Acyl,tRNA-Amino Acyl,Amino Acyl T RNA,Acyl tRNA, Amino,Acyl, tRNA-Amino,tRNA Amino Acyl,tRNA, Amino Acyl
D013347	Subcellular Fractions	Components of a cell produced by various separation techniques which, though they disrupt the delicate anatomy of a cell, preserve the structure and physiology of its functioning constituents for biochemical and ultrastructural analysis. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p163)	Fraction, Subcellular,Fractions, Subcellular,Subcellular Fraction
D015852	Eukaryotic Initiation Factor-2	Eukaryotic initiation factor of protein synthesis. In higher eukaryotes the factor consists of three subunits: alpha, beta, and gamma. As initiation proceeds, eIF-2 forms a ternary complex with Met-tRNAi and GTP.	EIF-2,Peptide Initiation Factor EIF-2,EIF-2 alpha,EIF-2 beta,EIF-2 gamma,EIF-2alpha,EIF-2beta,EIF-2gamma,EIF2,Eukaryotic Initiation Factor-2, alpha Subunit,Eukaryotic Initiation Factor-2, beta Subunit,Eukaryotic Initiation Factor-2, gamma Subunit,Eukaryotic Peptide Initiation Factor-2,EIF 2,EIF 2 alpha,EIF 2 beta,EIF 2 gamma,EIF 2alpha,EIF 2beta,EIF 2gamma,Eukaryotic Initiation Factor 2,Eukaryotic Initiation Factor 2, alpha Subunit,Eukaryotic Initiation Factor 2, beta Subunit,Eukaryotic Initiation Factor 2, gamma Subunit,Eukaryotic Peptide Initiation Factor 2,Initiation Factor-2, Eukaryotic,Peptide Initiation Factor EIF 2