The elongation factor 1 A-2 isoform from rabbit: cloning of the cDNA and characterization of the protein.
Nucleic Acids Res
; 26(8): 1884-90, 1998 Apr 15.
Article
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| MEDLINE
| ID: mdl-9518480
Eukaryotic elongation factor 1 A (eEF1A, formerly elongation factor-1 alpha) is an important component of the protein synthesis apparatus. Here we report the isolation and characterization of the cDNA sequence encoding rabbit eEF1A-2, an isoform of eEF1A, as well as a structural and functional comparison of the two rabbit isoforms. Northern analysis of the expression pattern of eEF1A-2 showed that this isoform is expressed in skeletal muscle, heart, brain and aorta, while transcripts are not detected in liver, kidney, spleen and lung. In contrast, the previously characterized eEF1A-1 isoform is expressed in all tissues examined except skeletal muscle. We have recently purified eEF1A-2 from rabbit skeletal muscle. By partial amino acid sequencing and determination of the post-translational modifications of eEF1A-2 we found that both of the glycerylphosphorylethanolamine modifications observed in eEF1A-1 appear to be present in eEF1A-2. However, two of the residues found dimethylated in eEF1A-1 appeared to be trimethylated in eEF1A-2. A comparison of the enzymatic activity showed that eEF1A-1 and eEF1A-2 have indistinguishable activity in an in vitro translation system. In contrast, the GDP dissociation rate constant is approximately 7 times higher for eEF1A-1 than for eEF1A-2. The nucleotide preference ratio (GDP/GTP) for eEF1A-1 was 0.82, while the preference ratio for eEF1A-2 was 1.50.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Factores de Elongación de Péptidos
Límite:
Animals
Idioma:
En
Revista:
Nucleic Acids Res
Año:
1998
Tipo del documento:
Article
País de afiliación:
Dinamarca
Pais de publicación:
Reino Unido