Sp8 transcription factor

Transcription factor Sp8 also known as specificity protein 8 (SP-8) or Btd transcription factor (buttonhead)^[5] is a protein that in humans is encoded by the SP8 gene.^[6][7] Sp8 is a transcription factor in the Sp/KLF family.

SP8
Identifiers
Aliases	SP8, BTD, Sp8 transcription factor
External IDs	OMIM: 608306; MGI: 2443471; HomoloGene: 18548; GeneCards: SP8; OMA:SP8 - orthologs
Gene location (Human) Chr. Chromosome 7 (human)[1] Band 7p21.1 Start 20,782,279 bp[1] End 20,786,886 bp[1]
Gene location (Mouse) Chr. Chromosome 12 (mouse)[2] Band 12|12 F2 Start 118,810,064 bp[2] End 118,816,311 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in pancreatic ductal cell sural nerve testicle ventricular zone gonad olfactory zone of nasal mucosa ganglionic eminence nasal epithelium mucosa of paranasal sinus muscle of thigh Top expressed in Rostral migratory stream olfactory bulb lateral septal nucleus primitive streak prostate respiratory epithelium olfactory epithelium lobe of prostate tail of embryo ventricular zone More reference expression data BioGPS n/a
Gene ontology Molecular function DNA binding metal ion binding nucleic acid binding DNA-binding transcription factor activity, RNA polymerase II-specific Cellular component nucleus Biological process proximal/distal pattern formation regulation of transcription, DNA-templated dorsal/ventral pattern formation embryonic limb morphogenesis transcription, DNA-templated regulation of transcription by RNA polymerase II Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 221833 320145 Ensembl ENSG00000164651 ENSMUSG00000048562 UniProt Q8IXZ3 Q8BMJ8 RefSeq (mRNA) NM_182700 NM_198956 NM_177082 NM_001379379 NM_001379380 RefSeq (protein) NP_874359 NP_945194 NP_796056 NP_001366308 NP_001366309 Location (UCSC) Chr 7: 20.78 – 20.79 Mb Chr 12: 118.81 – 118.82 Mb PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

Function

Sp8 mediates limb outgrowth during early development.^[5] Sp8 deletion in mice resulted in severe exencephaly.^[8] Sp8 is a zinc-finger transcription factor. The structural difference between Sp8 and Sp9 is only one amino acid. These transcription factors are Apical Ectodermal Ridge (AER) specific in limb development. The Apical Ectodermal Ridge signaling is important for specification of distal limb structures. Sp8 and Sp9 mediate Fgf10 signaling, which in turn regulates Fgf8 expression (Fgf10→Fgf8). Fgf8 is essential for normal limb development, and without the presence of Fgf8 in early development, there would be a decreased length of the limb bud and possible failure of the limb tissue develop. Both Sp8 and Sp9 have been found in vertebrates. Although, so far only Sp8 has been proven to be present in invertebrates too. Under lab conditions, Sp8 replaced btd in Drosophila, showing that Sp8 and btd both have similar functions in limb development in both vertebrates and invertebrates. Gene knockdown in zebrafish displayed that Fgf8 expression is necessary for appendage development.^[9]