5 replies to this topic

[justwonder]

Why should some Poly-A sequences lay upstream of a reporter gene?  

Thanks.

[george@CASE]

what specific vector is this?

[justwonder]

george@CASE, on Mar 23 2005, 12:56 PM, said:

what specific vector is this?

<{POST_SNAPBACK}>

It is a normal reporter vector where the Poly-A sequence lays upstream of the promoter of the reporter gene. Any ideas?  


Thanks.

[justwonder]

justwonder, on Mar 23 2005, 01:37 PM, said:

george@CASE, on Mar 23 2005, 12:56 PM, said:

what specific vector is this?

<{POST_SNAPBACK}>

It is a normal reporter vector where the Poly-A sequence lays upstream of the promoter of the reporter gene. Any ideas?  


Thanks.

<{POST_SNAPBACK}>

This is how the poly A sequence looks like. It lays upstream the SV40 promoter and is "used as transcriptional pause and for background reduction". What does it mean with that?    Thanks.

Edited by justwonder, 24 March 2005 - 07:58 AM.

[george@CASE]

thanks for the info. I'm GUESSING that it just introduces a break in possible transcription start sites aside from the SV40. It may also enhance expression of the reporter (??) in eukaryotic cells.

Like I said, it's just conjecture on my part.

Edited by george@CASE, 24 March 2005 - 11:59 AM.

[KevinK]

Dear justwonder,
   The synthetic poly(A) signal in the pCAT3 vector and several other Promega vectors is placed upstream of the reporter to eliminate background and vector dependent reporter signal.  Basically, all vectors have cryptic transcription factor binding sites that will cause the reporter to be transcribed.  By putting in a polyadenylation signal, these transcripts should no longer contain the reporter gene because it is spliced off and will not cause artificial signal.  I hope this is clear.  If you have any additional questions, please feel free to contact me at techserv@promega.com.

Regards,
Kevin

Technical Services Scientist
Promega Corporation