Hedgehog signaling Pathway

okay guys in this video tutorial we'll be talking about the hedgehog pathway which is one of the very important of pathway in developmental biology processes in mammal as well as in in arthropods and everyone so hedgehog pathway helps in the development of many different portions of your body like development of brain development of muscle gastrointestinal tract as well as development of your heart and all these things so so let me take a color here so here's your pathway named after the molecule Hedgehog capitulate small age this is the signaling molecule of this whole signal transduction pathway it is named after the signaling molecule so Hedgehog is a kind of chemical mediator that was secreted by the developing cell in the larval development in most of the cases because there so it's discovered develop during the larval development and this Hedgehog molecule is nothing but a segment polarity segment polarity genes is the segment polarity protein secreted in during the larva development of Drosophila in that case this segment polarity protein turn on certain signaling cascade which helps ultimately designate giving the larval development ultimately designate which is going to be the head and which is going to be the tail not tail I mean the end portion mouth and the opposite portion of the body and also it helps in the segmenting the larval body properly so there are three different kinds of this Hedgehog IH h IH h and so on so among them HHH is the most studied one that's called the sonic hedgehog and in sonic hedgehog is responsible to interact with another gene and another signaling system called winged les okay so this is another signaling system called wingless and also a segment polarity genes segment polarity signal cascade which we work together and finally provides the sequential development of the Drosophila larvae and sequential development of the different body segments of the Drosophila larvae and it's also true for any other arthropods which were having different segmentation of their body and it's very very important otherwise from where they need to have those legs and which segments won't have any leg and all these things are controlled because you know in our supports you will see that they always have this legs coming out from the from the upper part of the body not the lower part and that is due to this segment polarity signaling processes so hedgehog pathway is a type of pathway that connects other cells so it's an intercellular signaling pathway in this intracellular signaling pathway different cells will crossed off between themselves it helps in development of muscle else in development of lungs helps in development of GI tract and brain and so on and it's true for also in case of mammals so the idea the very basic representation of the signaling is let us say there are two different proteins onto the surface of a cell one is called patch another one is called the smooth end so patch and smoothing both on there the idea here smooth is not embedded in the membrane like that so this image is not exactly correct because movement is a protein which is inside a vesicle in the cytosol now patch is embedded in the membrane so multipass protein that is present in the membrane now normally when the signaling is not activated by any Hedgehog protein outside in that case patch is present and no signal I mean no signal is received by the target genes those are called the Leafs the target genes because ultimately those genes are controlled by the expression of GE plays a kind of protein signaling putting that we insert itself inside the nucleus and convey the signal inside the nucleus that is not possible if there is no Hedgehog molecule outside now if there is the hedgehog molecule outside because normally D is inactivated it is inactivated inside the cytosol but now once the Hedgehog molecule binds with the patch receptor on to the surface in that case it will bring this vascularized or vesicular Isner vesicular eyes a smoothing protein embedded to the membrane so this vesicle will come in and fuse with the membrane and as a result smooth will be embedded onto the membrane after binding of this Hedgehog and then finally this modem can activate this glee proteins and once the smooth will activate the Glee protein then Glee will go inside the cell and set the nucleus and it will turn on the Glee target genes and ultimately those genes will help the cell to develop the different organs to develop properly that's what we can see so as you can see it here this is patch this is moving and the patch action is always been regulated as its regulated by another protein called SH H which inhibits the functionality of patch and pull-offs the patch to bind it they need up any any of the Hedgehog signaling molecule now the thing is glee is not directly activated by smoothing because there are other intermediate Ori proteins to control that like GSK 3 beta P K you know GSK 3 beta is also component for tt signaling pathway we have already studied that if you haven't studied it you can go back and watch W into signaling which is also a very important signaling for this type of development in a GSK 3 beta inhibits this whole pathway similarly PKA it's also innovating this process PKA is a protein kindness and that is activated by cyclic AMP en cyclic am py gpcr g-protein coupled receptor signaling is playing a role here though in this case in different stages as you can see all of them are inhibitory stages that to block the expression of glia protein and this is extremely important because the signaling of smoothly through the glee ultimately turning on all those genes which will ultimately tell the cell to proliferate and differentiate to become a specific functional functional cell is very very important because all the genes that we see in all our cells are the same whatever genes are present in every cell are the same but still not cell functions differently than the muscle cell and the GI cells function differently than the lung cell and that's due to the expression of the cell and that's very very important their expression ability of a cell and that is the hugely important thing and that is controlled by several different of this cell signaling processes and hedgehog pathway is one of them definitely because hedgehog pathway you can see here direct pathways inhibited by so many different options like GSK 3 beta PKS you ape you so they can all inhibit these things so ultimately not activating this thing but if it is going to activate the only way to activate it is to bind with this h h2 attached me there that is the sonic hedgehog there to attach and then finally start this whole signal cascade finally turn on all these genes turning on I mean activating he 1 2 & 3 depending upon which kind of Hedgehog signaling molecule is binding and then it will turn on all those transcript gene transcription produce mRNA and produce proteins and then all those necessary things will start to up but that is the development and differentiation of the specific specific cell type like lungs GI tract cells it's like muscle cells and also new cells so these are the different development that he is associated with hedgehog pathway so if you liked this video please hit the like button subscribe to my channel to get more videos like that and also share this video a lot thank you

Channel: Shomu's Biology

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Keywords: suman bhattacharjee, shomus biology, biology online, biology courses, life science, biology major, Hedgehog signaling Pathway, Cell Signaling, Health (Industry), hedgehog pathway, hedgehog signaling, wnt signaling pathway, developmental biology, embryogenesis, Signal Transduction, cell signaling

Id: QwFss3BLqKM

Length: 8min 22sec (502 seconds)

Published: Mon Jun 15 2015