Is there a database that tells you which transcription factor influences a gene?
For example, if I wanted to know which TF influenced GFP15, is there a database that could quickly whip up this information?
In some organisms there are ChIP-seq data available (i.e.through UCSC genome browser). These might tell you if a TF is binding to your gene of interest, but it does not necessarily mean the TF regulates that gene (many TF binding sites are not functional regulatory elements).
Predicting TFs that regulate a gene de novo is pretty much impossible and I would be very skeptical of anyone saying they could do this for large genomes such as human and mouse. I certainly wouldn't pay for access to a database of predicted TF sites. Finding motifs is pretty much worthless, you will usually find binding sites for every TF under the sun if you search a gene promoter.
Another thing you might try is to look through microarray data of TF knockouts and see if any of them alter expression of your gene.