Regulation Akt/PKB signaling pathway

-


examples of feedback control in pi3k-akt pathway


the pi3k-akt pathway has many downstream effects , must regulated. 1 of ways pathway negatively regulated reducing pip3 levels. phosphatase , tensin homolog (pten) antagonises pi3k converting pi(3,4,5)p3 pi(4,5)p2. loss of pten function leads over-activation of akt , common in cancer cells (pten tumour suppressor). sh2-containing inositol phosphatase (ship) dephosphorylates pi(3,4,5)p3, @ 5 position of inositol ring. pi3k-akt pathway regulates pten levels affecting transcription , activity. transcription factor nf-κb, activated akt, regulates peroxisome proliferator-activated receptor delta (pparβ/δ) agonists , tumour necrosis factor α (tnfα), in turn repress pten expression. nedd4-1, e3 ligase recognises pten degradation up-regulated pi3k pathway. therefore, when akt activated, pten further repressed in positive feedback loop.


the pathway controlled protein phosphatase 2a (pp2a), dephosphorylates akt @ thr308 , phosphatase phlpp dephosphorylates akt @ ser473. protein important in akt attenuation carboxy terminal modulator protein (ctmp). ctmp binds regulatory domain of akt, blocking phosphorylation , activation.


when pathway activated insulin, insulin receptor substrate 1 (irs-1) transcription down-regulated, in negative feedback loop via mtorc1 , s6k1 activation. s6k1 able phosphorylate irs-1 @ multiple serine residues, preventing binding rtks. negative feedback control mechanism regulating pathway involves foxo transcription factors. activated akt causes foxo degradation, can no longer inhibit pp2a, leading decrease in akt phosphorylation.








Comments

Post a Comment

Popular posts from this blog

Causes Portuguese conquest of the Banda Oriental

-
the causes led king john vi of united kingdom of portugal, brazil , algarves, court had been installed in rio de janeiro since 1808, embark on invasion of banda oriental can divided general , circumstantial. among first located in main place, former portuguese aspiration bring frontiers of brazil coast of rio de la plata (portuguese: rio da prata), arguing matched tordesillas line spain , portugal had divided world in 1494. reason, region of rio de la plata border area between spain , portugal, , such, highly conflictive area , theater of bloody battles on centuries, after american colonies became independent of european powers. the río de la plata strategic because starting point of large river basin, fifth in world, goes heart of south america, near mining areas in potosi (current bolivia), through paraguay, mato grosso , reaching são paulo. additionally, banda oriental, in eighteenth , nineteenth centuries, area of major agricultural wealth, organized on old dairy , beef production,...
Read more

History The Vandals

-
1 history 1.1 years (1980-1984) 1.2 quackenbush, fitzgerald, , freese join (1984-1989) 1.3 role in 90s punk revival (1990-2000) 1.4 kung fu records years (2000-present) history early years (1980-1984) the vandals formed in 1980 in huntington beach, california guitarist jan nils ackermann. vocalist steven ronald stevo jensen (1959-august 21, 2005) found , , ackermann practiced , performed rotating cast of other members before permanent lineup coalesced include bassist steve human pfauter , drummer joe escalante. other members included steve gonzalez on bass , vince mesa on drums. the band built reputation in los angeles , orange county punk rock community included bands such bad religion, descendents, black flag, t.s.o.l., x, germs, suicidal tendencies, dickies, , social distortion. vandals distinguished in scene sticking humorous subject matter rather typical social , political topics addressed punk bands of time. the vandals performing in tucson, arizona in 1984, showing original...
Read more

Publications Daniel Kolak

-
1 publications 1.1 books 1.2 articles , chapters 1.3 papers , talks 1.4 lovers of wisdom website publications books the 3 pillars of wisdom, new york: rowman , littlefield, 2007. socrates on trial, new york: pearson/longman, 2007. philosophy of religion, new york: longman, 2007. cognitive science (w/ w. hirstein, p. mandik , j. waskan) london: routledge, 2006. the longman standard history of philosophy (w/ g. thomson), new york: pearson/longman, 2005. the longman standard history of 20th century philosophy (w/ g. thomson), pearson/longman, 2005. the longman standard history of 19th century philosophy (w/ g. thomson), pearson/longman, 2005. the longman standard history of modern philosophy (w/ g. thomson), new york: pearson/longman, 2005. the longman standard history of medieval philosophy (w/ g. thomson), new york: pearson/longman, 2005. the longman standard history of ancient philosophy (w/ g. thomson), new york: pearson/longman, 2005. i you: metaphysical foundations global ethics, do...
Read more