Question
These molecules bind to the V-beta chain of T-cell receptors, giving them a greater number of potential targets than those restricted to unique alpha and beta receptor clonotypes. For 10 points each:
[10h] Name these molecules that bind class II MHCs and T-cell receptors outside of the normal peptide-binding groove, resulting in T-cell overactivation. These molecules act as potent exotoxins in scarlet fever.
ANSWER: superantigens [accept SAgs; prompt on antigens]
[10e] Superantigen engagement causes T-cells to activate signaling through the Src (“sark”) family of kinases, which are enzymes that transfer these groups from donors like ATP to their substrates.
ANSWER: phosphates
[10m] In the absence of a Src kinase, SAgs activate T-cells through the activation of phospholipase C by the alpha-11 subunit of these proteins. These proteins couple with receptors that cross the cell membrane seven times.
ANSWER: G proteins [or guanine-nucleotide-binding proteins; accept heterotrimeric G proteins]
<AY, Biology>
Summary
| 2023 ARCADIA at Duke | Emory, Duke, Yale | Y | 4 | 2.50 | 25% | 0% | 0% |
| 2023 ARCADIA at Emory | Emory, Duke, Yale | Y | 4 | 10.00 | 100% | 0% | 0% |
| 2023 ARCADIA at Imperial | Imperial | Y | 5 | 10.00 | 60% | 40% | 0% |
| 2023 ARCADIA at Maryland | Maryland, Online | Y | 3 | 10.00 | 67% | 33% | 0% |
| 2023 ARCADIA at Ohio State | Ohio State, Texas | Y | 3 | 13.33 | 67% | 67% | 0% |
| 2023 ARCADIA Online | Maryland, Online | Y | 3 | 6.67 | 67% | 0% | 0% |
| 2023 ARCADIA at Texas | Ohio State, Texas | Y | 3 | 10.00 | 67% | 33% | 0% |
Data
| Johns Hopkins | George Washington B | 0 | 10 | 10 | 20 |
| Maryland A | Georgetown | 0 | 0 | 0 | 0 |
| George Washington A | Maryland B | 0 | 10 | 0 | 10 |