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A gene on chromosome 14q24.3 that encodes a leucine zipper DNA-binding FOS-type nuclear phosphoprotein, which dimerises with proteins of the JUN family to form the transcription factor complex AP1. FOS proteins regulate cell proliferation, differentiation and transformation, and may be associated with apoptosis.
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A family of cancer-causing genes, first identified in viruses, that function within cells as transcription factors. Members of this family can transform normal cells (e.g., fibroblasts) into cancer cells (e.g., osteosarcomas, chondrosarcomas). See: oncogene; transformation


The name is derived from “FBJ osteosarcoma virus, ” in which these oncogenes were first identified.

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References in periodicals archive ?
NF[kappa]B: nuclear factor-kappa B; STAT3: signal transducer and activator of transcription 3; AP-1: activator protein 1; Ac: acetyl group; Ub: ubiquitin.
Yuspa, "Activator protein 1 transcription factors are fundamental to v-ras(Ha)-induced changes in gene expression in neoplastic keratinocytes," Cancer Research, vol.
Baker et al., "Dominant-negative activator protein 1 (TAM67) targets cyclooxygenase2 and osteopontin under conditions in which it specifically inhibits tumorigenesis," Cancer Research, vol.
The newly identified cancer-gene-derived protein, triggered by an animal virus, resembles "activator protein 1," or AP-1, present in all normal cells.
NF-[kappa]B is known to interact with a large number of other transcription factors, including activator protein 1. (9) The activator protein 1 family of proteins consists of the Fos (cFos, Fos-B, Fos-related antigen 1 [FRA-1], and FRA-2) and Jun (c-Jun, Jun B, and Jun D) subfamilies.
Expression of FRA-1 was also studied, because FRA-1 belongs to the activator protein 1 family of transcription factors and members of this family are known to interact with NF-[kappa]B.
This is in agreement with the previously published finding of cross talk between p65 and Fos-Jun heterodimers of activator protein 1.23 Small upper panels in Figure 7 show activation (nuclear colocalization) of NF-[kappa]B and FRA-1 (left and right panel, respectively).
Growth of malignant cells could be regulated by various leptin-induced second messengers like STAT3 (signal transducers and activators of transcription 3), AP-1 (transcription activator protein 1), MAPK (mitogen-activated protein kinase) and ERKs (extracellular signal-regulated kinases).
Inhibition of activator protein 1 activity and neoplastic transformation by aspirin.
Inhibition of tumor promoter-induced activator protein 1 activation and cell transformation by tea polyphenols, (-)-epigallocatechin gallate, and theaflavins.