Intramembrane ligand-binding domain in transmembrane receptors?

[Dagl1]

Hi there,

Are there any transmembrane receptors (metabotropic or ionotropic) which have their ligand-binding domain located inside the membrane, and (if metabotropic) has G-proteins, kinases or other signalling proteins on the extracellular side?

I guess that it is possible for cells to 'misplace' their receptors and put them backwards or reversed inside the membrane. But are there any proteins which function regularly by having intracellular ligands bind and then mediating a signal to outside the membrane?

Thanks in advance,
Dagl

[poo thrower]

On 2/12/2020 at 11:59 AM, Dagl1 said:

I guess that it is possible for cells to 'misplace' their receptors and put them backwards or reversed inside the membrane. But are there any proteins which function regularly by having intracellular ligands bind and then mediating a signal to outside the membrane?

Thanks in advance,
Dagl

can you explain / example how they get their receptors "backwards" please ? (because that sounds to me like a "RNA error" (= "apoptosis" (?))

- i don't think so, because every cell needs to self-regulate, and does so by signalling to ITS OWN rRNA by the methods you have stated... and i believe it would be a big error to "signal outside" as opposed to apoptosis... but i dunno for certain, nor if that was infact what you were asking.

[Dagl1]

Thanks for the comment!
I don't really understand the relevance of (r)RNA in this case. Apoptosis is controlled cell death, but the thing I am wondering about is: are there any receptors which receive signals from the inside of the cell and mediates some sort of effect to the outside of the cell (while remaining stuck in the membrane).

Basically, are there any (for example ) GPCR's which have their ligand binding domain inside the cell, and their G-proteins present outside the plasma membrane.

I don't know of any such receptor, however I also don't see much reason why there wouldn't exist a few like that.  

-Dagl

Edit, to answer your question about how errors can occur (I would think they could occur, I didn't read any research showing cells putting receptors backwards, but since some (most?) receptors have to be assembled, there could be errors. 
It would of course be naive that every assembly process allows for a 'backwards' receptor, but I don't think it would be too strange to see some misassembly leading to a backwards receptors (basically it wouldn't surprise me if it existed). I may be unaware of some RNA>protein assembly signalling, but otherwise I doubt that it is primarily rRNA 'signalling' (? not really sure what that is;p).

Anyway, while it would be fascinating to see if there are any wrongly placed 'backwards' receptors, I am more interested in knowing if there are any naturally functioning receptor that mediate signalling from inside to outside with a ligand-binding domain on the intracellular part of the membrane.

Edited February 18, 2020 by Dagl1

[poo thrower]

On 2/18/2020 at 8:25 AM, Dagl1 said:

Thanks for the comment!
I don't really understand the relevance of (r)RNA in this case. Apoptosis is controlled cell death, but the thing I am wondering about is: are there any receptors which receive signals from the inside of the cell and mediates some sort of effect to the outside of the cell (while remaining stuck in the membrane).

i don't think you would get to see this because the cell would be post apoptosis already (i think / as above (?)).

Quote

G proteins, also known as guanine nucleotide-binding proteins, are a family of proteins that act as molecular switches inside cells, and are involved in transmitting signals from a variety of stimuli outside a cell to its interior

if they are the "wrong way around" then there can be "nothing to effect" (like rRNA ("protein synthesis") as example) - "the cell would be pointless" THUS apoptosis - (rRNA was just plucked from thin air i think as intended "cellular life versus death" juxtaposition).

it's a one way system i think with no exceptions as above / below (BUT i am not 100% (biology being biology....))

 

[Dagl1]

Sorry, but I think you are completely misunderstanding what my question is. Apoptosis does not play a role here and there is no reason for it to occur. 
I don't really understand what you are saying either way, but my question is just if there are any known proteins that have a ligand-binding domain inside the cell and their effector proteins outside...

[poo thrower]

9 hours ago, Dagl1 said:

Sorry, but I think you are completely misunderstanding what my question is. Apoptosis does not play a role here and there is no reason for it to occur. 
I don't really understand what you are saying either way, but my question is just if there are any known proteins that have a ligand-binding domain inside the cell and their effector proteins outside...

ok; but i think you maybe misunderstanding that i have told you NO 2x already (- if you kept your telephone outside of your house in the public domain you wouldn't be able to hear it ringing... (- it would quickly become another cells property))

i will stop posting in your thread on account of our obvious "crossed wires" with the following link that i hope will be helpful ?:

Quote

https://en.wikipedia.org/wiki/Microvesicles

 

[hypervalent_iodine]

2 minutes ago, poo thrower said:

ok; but i think you maybe misunderstanding that i have told you NO 2x already (- if you kept your telephone outside of your house in the public domain you wouldn't be able to hear it ringing... (- it would quickly become another cells property))

i will stop posting in your thread on account of our obvious "crossed wires" with the following link that i hope will be helpful ?:

 

!

Moderator Note

It seems more to me that you don't understand enough about the context of the actual question and are therefore (inadvertently) giving nonsensical answers. It is probably best you stop derailing the thread with what are really off-topic answers. Microvesicles really do not have anything to do with what Dagl1 is asking about.