Human rab11a: transcription, chromosome mapping and effect on the expression levels of host GTP‐binding proteins

FEBS Letters

Gromov, Pavel S.¹  Gromova, Irina¹  Tommerup, Niels²  Hansen, Claus²  Celis, Julio E.¹  Madsen, Peder¹ 

[1] Department of Medical Biochemistry and Danish Centre for Human Genome Research, Aarhus University, Ole Worms Allé 170, Build. 170, DK-8000 Aarhus, Denmark;Department of Medical Genetics, IMBG The Panum Institute, The University of Copenhagen Blegdamsvej 3, 2200 Copenhagen, Denmark

关键词: 2D PAGE;    GTP-binding protein;    ras family;    GTP;    guanosine 5′-triphosphate;    DTT;    dithiothreitol;    IEF;    isoelectric focusing;    2D PAGE;    two-dimensional polyacrylamide gel electrophoresis;   

DOI  :  10.1016/S0014-5793(98)00607-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Rab11a is a member of the rab-branch of the ras-like small GTP-binding protein superfamily that is associated with both constitutive and regulated secretory pathways. Using a direct procedure for cDNA cloning of small ras-related GTPases, that is based on the screening of eukaryotic cDNA expression libraries using [α-³²P]GTP as a probe, we have isolated two cDNA clones encoding rab11a. Both clones share identical coding sequences, but differ in the length and sequence of their 3′ untranslated regions (3′-UTR). Northern blot hybridisation analysis of various human tissues revealed indeed two mRNA species with lengths of 1.0 and 2.3 kb, respectively. Sequence analysis of the cDNAs identified two different putative polyadenylation signals (AATAAA) at positions 927 and 2302 of the larger transcript. In addition, the 3′-UTR of the larger transcript exhibited several AU-rich elements (ARE) that are believed to control gene expression by regulating the rate of mRNA degradation. Southern blots of human DNA digested with several rare restriction enzymes, and separated by pulse-field gel electrophoresis, yielded the same macro-restriction fragment pattern when hybridised with probes that discriminate between the two transcripts. Taken together, these findings imply that the two mRNA species originate from a single gene, which we have mapped to 15q21.3-q22.31, by the use of diferent polyadenylation sites. As expected, both rab11a-cDNAs yielded the same protein product when transiently expressed in COS-1 cells, and surprisingly, upregulated the proteome expression profile (de novo synthesis or posttranslational modification of preexisting proteins) of a few other, yet unknown GTP-binding proteins.

【 授权许可】

Unknown