Why few hubs control gene regulation? - (May/19/2007 )

I'm recently studying system biology, and think of a question.

Why gene control is mainly determined on few "hubs" that few transcription factors can regulate most of the gene expression?

What if one of the important hubs broken?

Isn't it risky to put all regulatory function on one few genes?


I'm wondering what everyone think of this question....
Thanks~

well, I would say that there are more than a few...there are a VAST number of transcription factors, each with their own specific roles

some of the global regulatory pathways could seem to cause a problem if there was a breakdown in the system, but you must also consider the amount of inherent redundancy in signaling pathways. there are generally several ways to get to the same place, in terms of how signaling pathways interconnect

that being said, when there is a major breakdown in a signaling system, likely the organism didn't survive gestation...or at the least, it could result in some major metabolic imbalance, or a real problem with the immune system. it all depends on where the problem is...