HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Sakurai, M. Articles by Sekikawa, K. Search for Related Content PubMed PubMed Citation Articles by Sakurai, M. Articles by Sekikawa, K. Agricola Articles by Sakurai, M. Articles by Sekikawa, K.

Construction and functional characterization of mutants of the bovine leukaemia virus trans-activator protein p34^tax

Atsuyoshi Taneda

Hiroyuki Nagoya^>

Biophysics Laboratory, National Institute of Animal Health, 3-1-1 Kannondai, Tsukuba, Ibaraki 305, Japan

The p34^tax protein [p38^tax, p34, p38(XBL), XBL-I] of bovine leukaemia virus (BLV) activates transcription from the BLV long terminal repeat (LTR) promoter. To analyse the functional properties of this protein, in frame insertions and internal deletions were systematically introduced in a plasmid-encoded copy of the p34^tax gene. The abilities of wild-type and mutant genes to activate gene expression from the LTR promoter linked to the chloramphenicol acetyltransferase gene and to inhibit trans-activation by the wild-type protein were studied. The trans-activating activity of 14 of the 18 mutants tested was completely abolished, but four mutants each containing a lesion in the internal portion of the polypeptide retained activity. Taken together, these results suggest the presence of an internal region of the polypeptide where structural integrity is less strictly required for the functional activity of this protein. Among the mutants incompetent in the transactivation assay, only two with mutations in the N-terminal region of the polypeptide inhibited trans-activation by the wild-type protein in a dose-dependent manner. These results facilitate understanding of the physiological function of the tax protein family.

Present address: Zen-noh Institute of Animal Health, 7 Ohjamachi, Sakura-shi, Chiba-ken 285, Japan.

^> Present address: National Research Institute of Aquaculture, Hiruta, Tamaki-cho, Watarai-gun, Mie-ken 519-04, Japan.

Received 15 April 1991; accepted 17 June 1991.