Intracellular signaling pathways that are participating in protein sorting and membrane traffic

Question

Hi!

I am studying biotechnology. Now I'm doing a course of Molecular biology of the Cell, and one of my tasks is to write an essay about "Intracellular signaling pathways". This essay topic is very broad, but my teacher restricted it to two chapters "Intracellular compartments and protein sorting" and "Membrane traffic". Well, now I don't know what to write, because, in my understanding, signaling pathways always mean the pathways in which, for example, GPCR and enzyme coupled receptors contribute.

I carefully read these chapters and perhaps came across something that I can catch on to and write an essay: GTPases of Ras superfamily, as Ran, Rab and ARF, also phosphoinositides which determine identity of membranes. Do these somehow belong to intracellular pathways, or am i totally wrong and need to find something else? If you have something in mind, can you give me a clue so I can catch a flow to write this quite interesting essay?

Answer 1

Hi Daria,

What an interesting topic! Yes, GPCR receptors would classify as an intracellular signalling pathway because upon dimerization after stimulation with a growth factor they will lead to a series of downstream activation of other proteins that will likely lead to altered phosphorylation of protein targets or transcription of related genes. Some good signaling pathways to look into would be the Beta-catenin pathway, Ras pathway, PTEN pathway or TNFalpha pathways. Alternatively, if you don't want to discuss a classical signalling pathway, protein secretory pathways may also be interesting! For instance, proteins that are secreted from cells (this is most common in cancer pathologies) often follow a classical ER-Golgi pathway which is "activated" by a signal sequence the target protein has.

I hope this helps with some ideas and good luck on your paper!

Sarah