Disease relevance of Qa2

• These results clearly demonstrate that the Qa-2 MHC antigen is involved in resistance to T. crassiceps cysticercosis [1].

High impact information on Qa2

• Major histocompatibility complex (MHC) class 1 molecules that were either transmembrane- (H-2Db) or glycosylphosphatidylinositol (GPI)-anchored (Qa2) were labeled with antibody-coated gold particles and moved across the cell surface with a laser optical tweezers until they encountered a barrier, the barrier-free path length (BFP) [2].
• Qa-region class I gene expression: identification of a second class I gene, Q9, encoding a Qa-2 polypeptide [3].
• Recently, the class I gene Q7 has been shown to encode a protein product that is biochemically indistinguishable from the lymphocyte-bound Qa-2 molecule [3].
• Utilizing gene transfection, we have identified a second Qa-2 subregion class I gene (Q9), in H-2b mice, which encodes a polypeptide biochemically similar to the Q7 and the Qa-2 polypeptides [3].
• Flow cytometric analysis revealed that L3T4+-activated T cells expressed lipase-sensitive Qa2 molecules, whereas Lyt-2+ cells express lipase-resistant forms of the Qa2 molecule [4].

Biological context of Qa2

• L-cells transfected with these genes did not express class I genes reacting with alloantisera or monoclonal antibodies against Qa2, Qa4 or TL differentiation antigens [5].
• It was suggested that resistance might correlate with expression of the nonclassic class I major histocompatibility complex (MHC) Qa-2 antigen; BALB/cAnN is Qa-2 negative and highly susceptible to T. crassiceps, whereas BALB/cJ expresses Qa-2 and is highly resistant [1].

Anatomical context of Qa2

• Qa-2 is glycosylphosphatidylinositol (GPI) linked in the cell membrane [6].

Associations of Qa2 with chemical compounds

• As a result, Qa-2 proteins cluster in cholesterol- and sphingolipid-rich lipid raft microdomains in the cell membrane and can signal via raft-associated intracellular signaling molecules [6].

Other interactions of Qa2

• Based on SDS-PAGE analysis, the secreted Qa2 molecules has a Mr of 39 kDa whereas the cell surface form released from either resting spleen or activated T cells by phosphatidylinositol-specific phospholipase C has a Mr of approximately equal to 40 kDa [4].

References