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Cellular mechanisms that control protien packing

  1. Aug 27, 2005 #1
    Hi. Sorry for bringing this up again, if somebody deems it necessary/good they can just delete this thread. If necessary I would even pay somebody to obtain this information; however this seems like a great place to get information like this. In fact, it seems like a spectacularly amazing forum and I'm sorry if I've ever offended anybody on it. It's a beautiful place and I wish I could contribute more to it. I would contribute to it more, if I knew the knowledge that everybody here seems to know...ah well maybe I will have lots of knowledge about biology eventually if I apply myself hard enough. The fact that I've never applied myself in regards to it in the past isn't an excuse for me not applying myself in regards to it in the future, I know.

    But I was wondering...

    could somebody give me the information that I want on the cellular mechanisms that control protien packing and/or tell me where I can get that information? I want to know whether (Things regarding the following paragraph below) would require more knowledge of the cellular mechanisms that control protein packing than is currently known. I also want to know who would have that knowledge of cellular mechanisms that control protein packing if that knowledge is known. Finally I might later like to know about stuff relating to some other concepts as a whole.

    Thanks

    The paragraph the above questions are in regards to:

    You would have to get the slime mold gene into the right part of the genome
    so that it is only expressed in the cells outside the organ in question. Hypothetically this should be possible since certain regions in the genome are turned on and off in different cells, so if you put this gene in a
    postion which is only transcribed by thse cells there shouldn't be a
    problem. Now, where things start getting really complicated is when you
    start talking about ensuring that the connecting protiens are sent to the
    cellular membrane. I don't know how this could be accomplished, and it
    sounds pretty difficult. This might require more knowlege of the cellular
    mechanisms that control protien packing than is currently known. However, I
    don't rule out the possibility that somebody somewhere in the world knows
    how to do it. It seems unlikely , though.
     
    Last edited: Aug 27, 2005
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  3. Aug 27, 2005 #2

    iansmith

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    First, inserting you gene of interest inside a specific region will not necessary means transcription under the desired condition. You woulkd have to insert a promoter that drive gene transcription under the desired conditions.
    Second, protein trafficking is control by chaperons and other proteins. These proteins recognise a specific amino acid sequence. So to have you protein transported to the membrane you would have insert in frame the appropriate signal peptides at the appropriate part of the gene. The DNA sequence of these peptides are fairly well known.

    You would need to get access to a university level cellular biology text book. NCBI has some free online book (at least some part of it).
    http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=Books

    and I recommed Molecular biology of the Cell
     
  4. Aug 27, 2005 #3
    Thanks. I had a little bit of trouble understanding what you said but...
    so the problem ISN'T that this would/might require more knowlege of the cellular mechanisms that control protien packing than is currently known?

    Thanks!
     
  5. Aug 27, 2005 #4

    iansmith

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    We have enough knowledge and we know that adding/removing a certain DNA sequence will affect the location of a protein. In bacteria and I think in some eukaryotes expression vectors, these DNA sequence are added to the gene you want to insert and you are able to surface express the protein.

    The biggest limitation would be the knowledge about the regulation of the genes in certain tissues.
     
  6. Aug 27, 2005 #5
    they are called Signal Recognition sequences and they are usually put at the N or C terminus. there are sequences for nuclear import/export, sequences to send proteins to the mitochondria, trans golgi complex, etc. KDEL is a C-term sequence that i remember which is essentially "return to ER". There is a repetitive sequence of arginines that will direct a protein through the nuclear pore complex, and so on.

    the book "Molecular Biology of the Cell" has a section on this. this book, i believe is even online at the NCBI website. You can get more specific information by looking through the BLAST database and searching the literature.
     
  7. Aug 27, 2005 #6
    sorry, i didn't see this. didn't mean to repeat what you said, iansmith.
     
  8. Aug 28, 2005 #7
    (I deleted/got rid of some posts of mine in this thread because I thought that the last one would be the most relevant and useful one and that, after the last post here was written by me, the other posts written by me (In this thread) became unnecessary)

    Anyways for some reason there are some posts that I made here which I cannot edit/delete because the edit button does not appear around them
     
    Last edited: Aug 29, 2005
  9. Aug 28, 2005 #8
    gene expression in different cell/tissue types can be done using Cre-Lox methods.

    this technique is too complicated to explain on a forum, but you can read about them in the literature.. to make a long story short, the gene that you want selectively turned on can be embedded in a LoxP site, and then you can control the expression of Cre (cyclic recombinase) as a function of tissue specific conditions (by sticking the cre gene in with a tissue-specific gene - or even in response to a drug such as tetracycline (the tet operon). since cre is from a bacteriophage, it is highly unlikely to be present in the tissues of eukaryotes.

    all of this involves embryonic gene manipulation, using homologous recombinant insertion (neomycin and thymidine kinase +/- gene selection). look up how "knock-out" mice are made for details.

    regarding the protein translocation - this has already been answered here by myself and iansmith.

    not to discourage you, but keep in mind that what you are proposing - to make a completely new organ, transgenically - has only been done in limited ways to date, by researchers with an incredible amount of experience in this field. what you are suggesting, abeit vaguely, may not even be possible between the species you have mentioned thus far.

    why are you so hung up on slime mold? perhaps i don't fully understand.
     
  10. Aug 28, 2005 #9
    Because slime molds can connect up to each other to form one organism

    Therefore, I was trying to see if it would be possible to use their genes to make an organ (Inside a multi-cellular organism like a cat) connect up to another organ (That was the same type of organ I guess)? It seems like the slime mold genes are the only genes that I could use somewhat because it seems like they're the only organisms which connect up to themselves to form one organism

    More specifically, I was wondering about whether or not you could connect one brain up to another brain in regards to the above, when I said I was wondering about whether or not you could connect up one organ to another organ

    So, this would not require require more knowlege of the cellular mechanisms that control protien packing than is currently known, despite the fact that that person said it might, right?

    Basically....I wanted a really really thorough explanation/summary of all the ways that I could do what I wanted to do (Preferrably one in laymans terms and one in scientific terms. I wouldn't necessarily need both of them though)...would the following paragraph be what I wanted? What would make the following paragraph be what I wanted better?

    You would have to get the slime mold gene into the right part of the genome
    so that it is only expressed in the cells outside the organ in question. Hypothetically this should be possible since certain regions in the genome are turned on and off in different cells, so if you put this gene in a postion which is only transcribed by thse cells there shouldn't be a problem. Now, where things start getting really complicated is when you start talking about ensuring that the connecting protiens are sent to the cellular membrane. I don't know how this could be accomplished, and it sounds pretty difficult. This might require more knowlege of the cellular mechanisms that control protien packing than is currently known. However, I don't rule out the possibility that somebody somewhere in the world knows how to do it. It seems unlikely , though.

    Thanks

    Of course I always wanted other relevant information if/when there is any opportunity to get that

    I'm sorry if I explained that in a really horrible way. I probably did. If nobody here can help me, perhaps that could point me in the direction of someone who could

    Thanks!
     
    Last edited: Aug 29, 2005
  11. Aug 29, 2005 #10

    iansmith

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    The problem with you idea is that other muticellular organism are already connected. People uses the slime mold as a model organism to understand why multiorganism connect and form organs. So if you express the slime molds gene, you might express genes that are already in the organism and you will not see an results.


    The knowledge about protein trafficking (it is a better term than packing) is sufficient to send a certain protein in specific desired area in or on the cell. However, the limited factor might be the expression of the protein in a specific tissue. We have some good knowledge about expression but it is limited.


    YOu should at least add this:
    First, you will need to contruct a protein expression cassette. To do so, the gene of interrest you have to be inserted after two specific DNA region. the first region would control the expression of the protein in a specific tissue and the other region would be the signal protein sequence required for proper localization of the protein in a specific the cellular area. Once this is constructed and inserted in the proper vector, the organism can be transformed.
     
  12. Aug 29, 2005 #11
    So if I wanted to use slime mold genes to make the brain of one multi-cellular organism (eg a cat) connect up to another brain (of the same type of organism?) I would use the following as a really thorough explanation/summary of how to do that? What ways could I make the following a more thorough explanation/summary (In layman's terms and/or scientific terms) of how to do that?

    Thanks

    First, you will need to contruct a protein expression cassette. To do so, the gene of interrest you have to be inserted after two specific DNA region. the first region would control the expression of the protein in a specific tissue and the other region would be the signal protein sequence required for proper localization of the protein in a specific the cellular area. Once this is constructed and inserted in the proper vector, the organism can be transformed.

    You would have to get the slime mold gene into the right part of the genome
    so that it is only expressed in the cells outside the organ in question. Hypothetically this should be possible since certain regions in the genome are turned on and off in different cells, so if you put this gene in a postion which is only transcribed by thse cells there shouldn't be a problem. Now, where things start getting really complicated is when you start talking about ensuring that the connecting protiens are sent to the cellular membrane. I don't know how this could be accomplished, and it sounds pretty difficult.
     
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