Immunofluorescence studies of human fibroblasts demonstrate the presence of the complex of elongation factor-1 beta gamma delta in the endoplasmic reticulum.
The eukaryotic elongation factor-1 (EF-1) consists of four subunits, EF-1 alpha, EF-1 beta, EF-1 gamma and EF-1 delta which induce efficient transfer of aminoacyl-tRNA to the ribosome. In this process EF-1 alpha.GTP acts as the carrier of the aminoacyl-tRNA on its way to the ribosome. After release of aminoacyl-tRNA to the ribosome under concomitant hydrolysis of GTP, the inactive EF-1 alpha.GDP form is recycled to EF-1 alpha.GTP by EF-1 beta gamma delta. In eukaryotic cells the concentration of EF-1 alpha exceeds that of the complex beta gamma delta by a factor of 5-10. In order to delineate the intracellular localization of the different subunits of EF-1, antibodies against the EF-1 subunits have been elicited and indirect immunofluorescence microscopy experiments were performed. In human fibroblasts, the guanine nucleotide exchange part of EF-1, EF-1 beta gamma delta, was found to co-localize with the endoplasmic reticulum (ER), displaying a distinct fine-structure in its staining pattern. The guanine nucleotide-binding subunit of EF-1, EF-1 alpha, shows a more diffuse distribution throughout the cytoplasm and is, in addition, associated with the nucleus.
Sanders
J
J
Department of Medical Biochemistry, Sylvius Laboratory, University of Leiden, The Netherlands.
Brandsma
M
M
Janssen
G M
GM
Dijk
J
J
Möller
W
W
D000595:Amino Acid Sequence; D002460:Cell Line; D002467:Cell Nucleus / Q000737:chemistry; D003593:Cytoplasm / Q000737:chemistry; D004721:Endoplasmic Reticulum / Q000737:chemistry*; D005347:Fibroblasts / Q000737:chemistry / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D006801:Humans; D008969:Molecular Sequence Data; D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors / Q000032:analysis* / Q000737:chemistry; D010446:Peptide Fragments / Q000032:analysis*
D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors; D010446:Peptide Fragments