4 replies to this topic

[Ricardo Luis]

when an extracellular  ligand like epinephrine is transduced into the cell, one biochemical pathway ends in the nucleus.

this signal activates some transcription factors such as CREB which binds an specific nucleotic  sequence in the DNA, this book (cell and molecular biology Gerald Karp p.633) says that " these trancription factors INCREASE THE RATE of initiation of transcription " i don´t understand it.

is it mean the transcription is always occuring? please help i love study cell biology is amazing

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[pito]

when an extracellular  ligand like epinephrine is transduced into the cell, one biochemical pathway ends in the nucleus.

this signal activates some transcription factors such as CREB which binds an specific nucleotic  sequence in the DNA, this book (cell and molecular biology Gerald Karp p.633) says that " these trancription factors INCREASE THE RATE of initiation of transcription " i don´t understand it.

is it mean the transcription is always occuring? please help i love study cell biology is amazing

 

Have you looked at the wikipedia page describing CREB?

 

In general: transcription is always occuring... at any time in our body there is transcription of certain genes.

Transcription is not just a yes/no story. Its much more detailed.

In 1 cell you can have transcription of gene A, in another cell there is not transcription of gene A. Its a very delicate balance and hard to just explain as a yes/no story.

 

Have you looked into transcription in general? The transcription factors? Basal level? And so on?

[Ricardo Luis]

so, is not neccessary a extracellular signal to start a genetic transcription?

sorry i am new in this topic thanks

[pito]

so, is not neccessary a extracellular signal to start a genetic transcription?

sorry i am new in this topic thanks

well... your question is harder to answer than you think.

 

Is it necessary? Yes and no! Haha It all depends on the genes..

Some genes will have a basel transcription all the time and will hardly change. Others have a basal transcription but will be upregulated following certain stress or downregulated.

Others will be very much influenced by extracellular signals , others will not.

 

It is hard to say.

Its a very complex system and I believe that we do not even know everything about it. Even now things are discovered. Many genes/proteins are also linked to each other and it is really not a black-white question.

 

 

Check the paper I attached, it will already give you much information.

Its a chapter on gene regulation/expression.

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•  regulation gene expression.pdf   797.02KB   855 downloads

[Ricardo Luis]

 

so, is not neccessary a extracellular signal to start a genetic transcription?

sorry i am new in this topic thanks

well... your question is harder to answer than you think.

 

Is it necessary? Yes and no! Haha It all depends on the genes..

Some genes will have a basel transcription all the time and will hardly change. Others have a basal transcription but will be upregulated following certain stress or downregulated.

Others will be very much influenced by extracellular signals , others will not.

 

It is hard to say.

Its a very complex system and I believe that we do not even know everything about it. Even now things are discovered. Many genes/proteins are also linked to each other and it is really not a black-white question.

 

 

Check the paper I attached, it will already give you much information.

Its a chapter on gene regulation/expression.

 

when i started to learn cell signaling i said it would be easy but it isnt true haha. anyway i like this topic.