Recent content by None

I do know that some secreted proteins in bacteria have their own translocation domains, ie. type V secretion systems. Wouldn't be too far fetched to say that some eukaryotic ER components could encode self translocators specific for ER membranes, though I don't know of any specific examples.

We'd definitely have to learn more about human DNA regulation

Thats exactly it Monique, and its only through restrictions such as the one you stated in the US that we can keep our motivations in check (and I believe that they are imposed in a large part due to public awareness and the general consensus of a population that this research is wrong). In this...

Diabetes is a result of an autoimmune reaction, where the body produces antibodies against B-islet cells in the pancreas which produce insulin. As for the poll, I definitely feel there is great potential from stem cell research. Its more an ethical question you're posing though, and science...

Lately in a biomedical ethics class I am enrolled in, we've been discussing the underlying values and moral issues involved in testing on non-human animals. Most ethical theories advocating the use of animals in research run into trouble when they attempt to draw a line between humans, and...

Lately in a biomedical ethics class I am enrolled in, we've been discussing the underlying values and moral issues involved in testing on non-human animals. Most ethical theories advocating the use of animals in research run into trouble when they attempt to draw a line between humans, and...

Just to add to AG's explanation of RNA: RNA can also have enzymatic activity, by forming three dimensional conformations and complexing with protein subunits. Ribosomes have this characteristic. None

The processing mechanism is a little bit more complex, and it differs depending on what type of antigen you're talking about (ie. extracellular vs. intracellular). For example there is a multisubunit protein called the proteosome that cleaves peptide in MHCII presentation. The main idea...

Good assumption Jikx, but MHC presents small fragments of peptide, not the entire protein - around 10 amino acids.(Though it differs depending on the class of MHC) For cytoplasmic proteins, think about what happens if that cell lyses, all its contents are open to the extracellular...

Thanks a lot for the scans iansmith, I'm not talking about proliferation of the B-Cells though, which is what that first slide is describing :smile: Rearrangement is definitely not random! Like you say in this paragraph, Mature B-Cell exhibit an Ig with a single antigenic specificity...

Thanks Nautica I agree... This all sort of has to do with my initial question, what is regulating the cytokine secretion that is responsible for isotype switching? If I could figure that out, the rest would most likely be visible immediately. None.

Try and think of it from a biochemical perspective! But first, some clarifying... Iansmith has been talking about negative and positive selection in the thymus. First off, TCRs (T-Cell receptors) have two different binding sites, one for antigen/MHC and one for the MHC itself (this is how...

Dunno if anyone that reads these boards has a background with Immunology, but here goes. As far as I understand it, heavy chain isotypes can switch on any given mature B cell due to the presence of Switch regions at the 3' of any isotype gene exon. This is regulated largely by cytokines that...