Mutations signaling

N-ras mutation Signal transduction Guanine diphosphate (GDP)/ guanine triphosphate (GTP) binding protein Acute myeloid leukemia, neuroblastoma... 

K-rfls mutation Signal transduction GDP/GTP binding protein Leukemia, lymphoma... 

Positive (ALS mice) or negative (wild-type mice) identification of the human mutate signal... 

Courtois G, Gilmore TD (2006) Mutations in the NF-kB signaling pathway implications for human disease. Oncogene 25 6831-6843... 

Ras is a G protein that cycle between two conformations, an activated Ras-GTP or inactivated form Ras-GDP. Ras, attached to the cell membrane by lipidation, is a key component in many signalling cascades, which couple growth factor receptors to downstream effectors that control such processes as cytoskeletal integrity, proliferation, cell adhesion, apoptosis and cell migration. Mutations and dysregulations of the Ras protein leading to increased invasion and metastasis, and decreased apoptosis are very common in cancers. 

TRAM is subject to control through phosphorylation by protein kinase C-e. It is phosphorylated on serine 16 which is located close to the myristoylation site which is TRAM cannot signal without this phosphorylation or if the myristoylation site has been mutated. 

What could be the signal for the induction of the cold shock proteins It has been observed that shifting E. coli cells from 37 to 5 °C results in an accumulation of 70S monosomes with a concomitant decrease in the number of polysomes [129]. Further, it has been shown that a cold shock response is induced when ribosomal function is inhibited, e.g. by cold-sensitive ribosomal mutations [121] or by certain antibiotics such as chloramphenicol [94]. These data indicate that the physiological signal for the induction of the cold shock response is inhibition of translation caused by the abrupt shift to lower temperature. Then, the cold shock proteins RbfA, CsdA and IF2 associate with the 70S ribosomes to convert the cold-sensitive nontranslatable ribosomes into cold-resistant translatable ribosomes. This in turn results in an increase in cellular protein synthesis and growth of the cells. 

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