title: A universal tag for recombinant proteins.
abstract: Incorporation of tags into recombinant proteins can facilitate their identification and purification. In addition, these tags can also be used to monitor the trafficking or localization of the recombinant proteins inside the cells. Several such tags have been developed. However, the lengths of these tags make it cumber-some to incorporate them into the desired proteins. Typically, one must subclone the desired cDNA into a plasmid containing the tag sequence at a suitable restriction site or ligate a synthetic oligonucleotide containing the tag sequence at a suitable restriction site in the cDNA of the desired protein. These manipulations can be avoided, if one uses a short peptide tag that can be incorporated by PCR. We show here that a short peptide tag, RYIRS can be easily incorporated at the C termini of recombinant proteins by PCR. We also showed that by using a mAb specific for this peptide sequence, the tagged proteins could be easily detected in Western blot analysis, immunofluorescence staining, and immunoprecipitation. The interactions between this tag sequence and the mAb have been well characterized. One can take advantage of this information and control the reactivities between the tagged proteins and the mAb by varying the lengths of the peptide tags. Furthermore, we showed that this tag can be used to monitor whether a recombinant protein is properly translated and terminated because the interactions between this tag sequence and the mAb requires that the tag be at the C-terminus of the protein.
authors.affiliation: Department of Molecular Pathology, University of Texas M.D. Anderson Cancer Center, Houston 77030, USA.
authors.forename: W
authors.initials: W
authors.lastname: Luo
authors.forename: T C
authors.initials: TC
authors.lastname: Liang
authors.forename: J M
authors.initials: JM
authors.lastname: Li
authors.forename: J T
authors.initials: JT
authors.lastname: Hsieh
authors.forename: S H
authors.initials: SH
authors.lastname: Lin
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D015415:Biomarkers; D015153:Blotting, Western / Q000379:methods*; D000939:Epitopes; D015336:Molecular Probe Techniques; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000302:isolation & purification*
chemical_list: D015415:Biomarkers; D000939:Epitopes; D011994:Recombinant Proteins