Transcription factor Sp1 explained

Transcription factor Sp1, also known as specificity protein 1* is a protein that in humans is encoded by the SP1 gene.[1]

Function

The protein encoded by this gene is a zinc finger transcription factor that binds to GC-rich motifs of many promoters. The encoded protein is involved in many cellular processes, including cell differentiation, cell growth, apoptosis, immune responses, response to DNA damage, and chromatin remodeling. post-translational modifications such as phosphorylation, acetylation, O-GlcNAcylation, and proteolytic processing significantly affect the activity of this protein, which can be an activator or a repressor.[1]

In the SV40 virus, Sp1 binds to the GC boxes in the regulatory sequence of the genome.

Structure

SP1 belongs to the Sp/KLF family of transcription factors. The protein is 785 amino acids long, with a molecular weight of 81 kDa. The SP1 transcription factor contains two glutamine-rich activation domains at its N-terminus that are believed to be necessary for promoter trans-activation.[2] SP1 most notably contains three zinc finger protein motifs at its C-terminus, by which it binds directly to DNA and allows for interaction of the protein with other transcriptional regulators. Its zinc fingers are of the Cys2/His2 type and bind the consensus sequence 5'-(G/T)GGGCGG(G/A)(G/A)(C/T)-3' (GC box element).Some 12,000 SP-1 binding sites are found in the human genome.[3]

Applications

Sp1 has been used as a control protein to compare with when studying the increase or decrease of the aryl hydrocarbon receptor and/or the estrogen receptor, since it binds to both and generally remains at a relatively constant level.[4]

Recently, a putative promoter region in FTMT, and positive regulators

Notes and References

  1. Web site: Entrez Gene: Sp1 transcription factor .
  2. Li L, He S, Sun JM, Davie JR . Gene regulation by Sp1 and Sp3 . Biochemistry and Cell Biology = Biochimie et Biologie Cellulaire . 82 . 4 . 460–471 . August 2004 . 15284899 . 10.1139/o04-045 .
  3. Zhang B, Song L, Cai J, Li L, Xu H, Li M, Wang J, Shi M, Chen H, Jia H, Hou Z . The LIM protein Ajuba/SP1 complex forms a feed forward loop to induce SP1 target genes and promote pancreatic cancer cell proliferation . Journal of Experimental & Clinical Cancer Research . 38 . 1 . 205 . May 2019 . 31101117 . 6525466 . 10.1186/s13046-019-1203-2 . free .
  4. Wormke M, Stoner M, Saville B, Walker K, Abdelrahim M, Burghardt R, Safe S . The aryl hydrocarbon receptor mediates degradation of estrogen receptor alpha through activation of proteasomes . Molecular and Cellular Biology . 23 . 6 . 1843–55 . March 2003 . 12612060 . 149455 . 10.1128/MCB.23.6.1843-1855.2003 .