 | This article needs additional citations for verification .(December 2011) (Learn how and when to remove this template message) |
SAP1A is one of a family of proteins that contains a unique DNA binding domain termed the ETS domain.
| | This article needs additional citations for verification .(December 2011) (Learn how and when to remove this template message) |
SAP1A is one of a family of proteins that contains a unique DNA binding domain termed the ETS domain.
The transcriptional activation domain of SAP1a resides within the C-terminal region, the function of which may be impeded by the N-terminus. Several potential ERK consensus sites within the C-terminal region of SAP1a can modulate its transactivation efficacy, implicating that SAP1a is a direct target of ERKs. [1]
SAP1a has been shown to interact with the c-fos serum response element upon recruitment by the serum response factor.
SAP1a is a nuclear protein stimulating transcription via the c-fos serum response element, and additionally via an Ets binding site independently of the serum response factor. [1]
Insulin activated the human INSIG2 promoter in a process mediated by phosphorylated SAP1a. [2]
Sap1a is phosphorylated efficiently by ERKs but not by SAPK/JNKs. Serum response factor-dependent ternary complex formation by Sap1a is stimulated by ERK phosphorylation but not by SAPK/JNKs. Moreover, Sap1a-mediated transcription is activated by mitogenic signals but not by cell stress. [3]
ELK1 and SAP1a have been shown to form ternary complexes with SRF on the serum response elements (SRE) located in the c-fos promoter. ELK1, SAPla, FLI1 and EWS-FLI1 are able to form ternary complexes with SRF on EGR1 SREs. In addition, ELK1 and SAP1a can also form quaternary complexes on the Egr1 SREI. [4]
SAP1a activation by ERK may play an important role in the transformation of extracellular stimuli into a nuclear response. [1]
Members of the signal transducer and activator of transcription (STAT) protein family are intracellular transcription factors that mediate many aspects of cellular immunity, proliferation, apoptosis and differentiation. They are primarily activated by membrane receptor-associated Janus kinases (JAK). Dysregulation of this pathway is frequently observed in primary tumors and leads to increased angiogenesis which enhances the survival of tumors and immunosuppression. Gene knockout studies have provided evidence that STAT proteins are involved in the development and function of the immune system and play a role in maintaining immune tolerance and tumor surveillance.
Sterol regulatory element-binding proteins (SREBPs) are transcription factors that bind to the sterol regulatory element DNA sequence TCACNCCAC. Mammalian SREBPs are encoded by the genes SREBF1 and SREBF2. SREBPs belong to the basic-helix-loop-helix leucine zipper class of transcription factors. Unactivated SREBPs are attached to the nuclear envelope and endoplasmic reticulum membranes. In cells with low levels of sterols, SREBPs are cleaved to a water-soluble N-terminal domain that is translocated to the nucleus. These activated SREBPs then bind to specific sterol regulatory element DNA sequences, thus upregulating the synthesis of enzymes involved in sterol biosynthesis. Sterols in turn inhibit the cleavage of SREBPs and therefore synthesis of additional sterols is reduced through a negative feed back loop.
In the fields of molecular biology and genetics, c-Fos is a proto-oncogene that is the human homolog of the retroviral oncogene v-fos. It was first discovered in rat fibroblasts as the transforming gene of the FBJ MSV. It is a part of a bigger Fos family of transcription factors which includes c-Fos, FosB, Fra-1 and Fra-2. It has been mapped to chromosome region 14q21→q31. c-Fos encodes a 62 kDa protein, which forms heterodimer with c-jun, resulting in the formation of AP-1 complex which binds DNA at AP-1 specific sites at the promoter and enhancer regions of target genes and converts extracellular signals into changes of gene expression. It plays an important role in many cellular functions and has been found to be overexpressed in a variety of cancers.
c-Jun is a protein that in humans is encoded by the JUN gene. c-Jun, in combination with c-Fos, forms the AP-1 early response transcription factor. It was first identified as the Fos-binding protein p39 and only later rediscovered as the product of the JUN gene. c-jun was the first oncogenic transcription factor discovered. The proto-oncogene c-Jun is the cellular homolog of the viral oncoprotein v-jun. The viral homolog v-jun was discovered in avian sarcoma virus 17 and was named for ju-nana, the Japanese word for 17. The human JUN encodes a protein that is highly similar to the viral protein, which interacts directly with specific target DNA sequences to regulate gene expression. This gene is intronless and is mapped to 1p32-p31, a chromosomal region involved in both translocations and deletions in human malignancies.
Mitogen-activated protein kinase 3, also known as p44MAPK and ERK1, is an enzyme that in humans is encoded by the MAPK3 gene.
Protein C-ets-1 is a protein that in humans is encoded by the ETS1 gene. The protein encoded by this gene belongs to the ETS family of transcription factors.
Dual-specificity mitogen-activated protein kinase kinase 4 is an enzyme that in humans is encoded by the MAP2K4 gene.
ETS Like-1 protein Elk-1 is a protein that in humans is encoded by the ELK1. Elk-1 functions as a transcription activator. It is classified as a ternary complex factor (TCF), a subclass of the ETS family, which is characterized by a common protein domain that regulates DNA binding to target sequences. Elk1 plays important roles in various contexts, including long-term memory formation, drug addiction, Alzheimer's disease, Down syndrome, breast cancer, and depression.
Friend leukemia integration 1 transcription factor (FLI1), also known as transcription factor ERGB, is a protein that in humans is encoded by the FLI1 gene, which is a proto-oncogene.
ETS translocation variant 4 (ETV4), also known as polyoma enhancer activator 3 (PEA3), is a member of the PEA3 subfamily of Ets transcription factors.
Early growth response protein 2 is a protein that in humans is encoded by the EGR2 gene. EGR2 is a transcription regulatory factor, containing three zinc finger DNA-binding sites, and is highly expressed in a population of migrating neural crest cells. It is later expressed in the neural crest derived cells of the cranial ganglion. The protein encoded by Krox20 contains two cys2his2-type zinc fingers. Krox20 gene expression is restricted to the early hindbrain development. It is evolutionarily conserved in vertebrates, humans, mice, chicks, and zebra fish. In addition, the amino acid sequence and most aspects of the embryonic gene pattern is conserved among vertebrates, further implicating its role in hindbrain development. When the Krox20 is deleted in mice, the protein coding ability of the Krox20 gene is diminished. These mice are unable to survive after birth and exhibit major hindbrain defects. These defects include but are not limited to defects in formation of cranial sensory ganglia, partial fusion of the trigeminal nerve (V) with the facial (VII) and auditory (VII) nerves, the proximal nerve roots coming off of these ganglia were disorganized and intertwined among one another as they entered the brainstem, and there was fusion of the glossopharyngeal (IX) nerve complex.
Serum response factor, also known as SRF, is a transcription factor protein.
Transcription factor PU.1 is a protein that in humans is encoded by the SPI1 gene.
RNA-binding protein EWS is a protein that in humans is encoded by the EWSR1 gene on human chromosome 22, specifically 22q12.2. This region of chromosome 22 encodes the N-terminal transactivation domain of the EWS protein and that region may become joined to one of several other chromosomes which encode various transcription factors, see The expression of a chimeric protein with the EWS transactivation domain fused to the DNA binding region of a transcription factor generates a powerful oncogenic protein causing Ewing sarcoma and other members of the Ewing family of tumors. These translocations can occur due to chromoplexy, a burst of complex chromosomal rearrangements seen in cancer cells. The normal EWS gene encodes an RNA binding protein closely related to FUS (gene) and TAF15, all of which have been associated to amyotrophic lateral sclerosis.
ERG is an oncogene. ERG is a member of the ETS family of transcription factors. The ERG gene encodes for a protein, also called ERG, that functions as a transcriptional regulator. Genes in the ETS family regulate embryonic development, cell proliferation, differentiation, angiogenesis, inflammation, and apoptosis.
ETS domain-containing protein Elk-4 is a protein that in humans is encoded by the ELK4 gene.
ETS domain-containing protein Elk-3 is a protein that in humans is encoded by the ELK3 gene.
In the field of molecular biology, the ETSfamily is one of the largest families of transcription factors and is unique to animals. There are 29 genes in humans, 28 in the mouse, 10 in Caenorhabditis elegans and 9 in Drosophila. The founding member of this family was identified as a gene transduced by the leukemia virus, E26. The members of the family have been implicated in the development of different tissues as well as cancer progression.
MAPK phosphatases (MKPs) are the largest class of phosphatases involved in down-regulating Mitogen-activated protein kinases (MAPK) signaling. MAPK signalling pathways regulate multiple features of development and homeostasis. This can involve gene regulation, cell proliferation, programmed cell death and stress responses. MAPK phosphatases are therefore important regulator components of these pathways.
EWS/FLI1 is an oncogenic protein that is pathognomonic for Ewing sarcoma. It is found in approximately 90% of all Ewing sarcoma tumors with the remaining 10% of fusions substituting one fusion partner with a closely related family member.