Definitions for ARAF
araf

WikipediaRate this definition:0.0 / 0 votes

1. ARAF

   Serine/threonine-protein kinase A-Raf or simply A-Raf is an enzyme that in humans is encoded by the ARAF gene. A-Raf is a member of the Raf kinase family of serine/threonine-specific protein kinases.Compared to the other members of this family (Raf-1 and B-Raf), very little is known about A-Raf. It seems to share many of the properties of the other isoforms, but its biological functions are not as thoroughly researched. All three Raf proteins are involved in the MAPK signaling pathway. There are several ways A-Raf is different from the other Raf kinases. A-Raf is the only steroid hormone-regulated Raf isoform. In addition, the A-Raf protein has amino acid substitutions in a negatively charged region upstream of the kinase domain (N-region). This could be responsible for its low basal activity.Like Raf-1 and B-Raf, A-Raf activates MEK proteins which causes the activation of ERK and ultimately leads to cell cycle progression and cell proliferation. All three Raf proteins are located in the cytosol in their inactive state when bound to 14-3-3. In the presence of active Ras, they translocate to the plasma membrane. Among the Ras kinase family, A-Raf has the lowest kinase activity towards MEK proteins in the Raf kinase family. Thus, it is possible that A-Raf has other functions outside the MAPK pathway or that it helps the other Raf kinases activate the MAPK pathway. In addition to phosphorylating MEK, A-Raf also inhibits MST2, a tumor suppressor and proapoptotic kinase not found in the MAPK pathway. By inhibiting MST2, A-Raf can prevent apoptosis from occurring. However, this inhibition is only possible when the splice factor heterogenous nuclear ribonucleoprotein H (hnRNP H) maintains the expression of a full-length A-Raf protein. Tumorous cells often overexpress hnRNP H. When hnRNP H is downregulated, the A-RAF gene is alternatively spliced. This prevents the expression of full-length A-Raf protein. Thus, overexpression of hnRNP H in tumor cells leads to full-length expression of A-Raf which then inhibits apoptosis, allowing cancerous cells that should be destroyed to stay alive. A-Raf also binds to pyruvate kinase M2 (PKM2), again outside the MAPK pathway. PKM2 is an isozyme of pyruvate kinase that is responsible for the Warburg effect in cancer cells. A-Raf upregulates the activity of PKM2 by promoting a conformational change in PKM2. This causes PKM2 to transition from its low-activity dimeric form to a highly active tetrameric form. In cancer cells, the ratio between dimeric and tetrameric forms of PKM2 determines what happens to glucose carbons. If PKM2 is in the dimeric form, glucose is channeled into synthetic processes such as nucleic acid, amino acid, or phospholipid synthesis. If A-Raf is present, PKM2 is more likely to be in the tetrameric form. This causes more glucose carbons to be converted to pyruvate and lactate, producing energy for the cell. Thus, A-Raf can be linked to energy metabolism regulation and cell transformation, both of which are very important in tumorigenesis.In addition, researchers have proposed a model of how A-Raf is linked to endocytosis. Upstream of A-Raf, receptor tyrosine kinases (RTKs) are activated, leading to RAS-mediated activation of Raf kinases, including A-Raf. Once activated, A-Raf binds to membranes rich in Phosphatidylinositol 4,5-bisphosphate (PtdIns (4,5)P2 and signals endosomes. This leads to activation of ARF6, a central regulator of endocytic trafficking.

WikidataRate this definition:3.3 / 4 votes

1. Araf

   Araf is the Muslim sheol or borderland between heaven and hell for those who are, from incapacity, neither morally bad nor morally good. Araf is also a partition. Between hell and paradise there is a high wall, an a'raf. On this partition stand men who have escaped from hell but who are not permitted to enter paradise. They yearn to enter paradise, but their sins and virtues are evenly balanced.

The Nuttall EncyclopediaRate this definition:4.0 / 1 vote

1. Araf

   the Mohammedan sheol or borderland between heaven and hell for those who are from incapacity either not morally bad or morally good.

Suggested ResourcesRate this definition:0.0 / 0 votes

1. ARAF

   What does ARAF stand for? -- Explore the various meanings for the ARAF acronym on the Abbreviations.com website.

How to pronounce ARAF?

1. Alex

   US English

   David

   US English

   Mark

   US English

   Daniel

   British

   Libby

   British

   Mia

   British

   Karen

   Australian

   Hayley

   Australian

   Natasha

   Australian

   Veena

   Indian

   Priya

   Indian

   Neerja

   Indian

   Zira

   US English

   Oliver

   British

   Wendy

   British

   Fred

   US English

   Tessa

   South African

How to say ARAF in sign language?

Numerology

1. Chaldean Numerology

   The numerical value of ARAF in Chaldean Numerology is: 3

2. Pythagorean Numerology

   The numerical value of ARAF in Pythagorean Numerology is: 8

Examples of ARAF in a Sentence

1. The IAAF:

   All athletes were caught under the IAAF ABP program although, as per IAAF Rules, the cases are sent to the Russian Federation( ARAF) for adjudication, the IAAF is satisfied that we have found aggravating circumstances in all cases, as we requested when referring the case to the Russian authorities.

2. The IAAF Council:

   IAAF Council was today informed that written confirmation had been received yesterday from ARAF (All Russia Athletics Federation) accepting their full suspension without requesting a hearing as was their constitutional right, aRAF confirmed they understood that Council would only accept their reinstatement as an IAAF member following the recommendation of the IAAF inspection team who will decide if the verification criteria have been fulfilled. ARAF confirmed they will cooperate fully and actively with the team.

References

1. ^ Wikipedia
   https://en.wikipedia.org/wiki/Araf
2. ^ Wikidata
   https://www.wikidata.org/w/index.php?search=ARAF
3. ^ The Nuttall Encyclopedia
   https://www.gutenberg.org/cache/epub/12342/pg12342-images.html#Araf