HLA class II histocompatibility antigen, DQ alpha 1 chain Recombinant Protein | DQA1 recombinant protein

Recombinant Human HLA class II histocompatibility antigen, DQ alpha 1 chain protein

Cat. Num. AAA9422023

• Gene Names: HLA-DQA1; DQ-A1; CELIAC1; HLA-DQA
• Reactivity: Human
• Purity: Greater than 90% as determined by SDS-PAGE.
• Synonyms: HLA class II histocompatibility antigen; DQ alpha 1 chain; Recombinant Human HLA class II histocompatibility antigen; DQ alpha 1 chain protein; DC-1 alpha chainDC-alphaHLA-DCAMHC class II DQA1; DQA1 recombinant protein

• Host: E Coli
• Reactivity: Human
• Purity/Purification: Greater than 90% as determined by SDS-PAGE.
• Form/Format: 20mM Tris-HCl based buffer, pH8.0
• Sequence Positions: Extracellular Domain, 24-213aa

• Tag Info: His-tag
• Preparation and Storage: Store at -20 degree C, for extended storage, conserve at -20 degree C or -80 degree C. Repeated freezing and thawing is not recommended. Store working aliquots at 4 degree C for up to one week.

Related Product Information for DQA1 recombinant protein

Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents th on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route, where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules, and for this reason this antigen presentation pathway is usually referred to as exogenous. As mbrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments, exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides, autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs, other cells of the gastrointestinal tract, such as epithelial cells, express MHC class II molecules and CD74 and act as APCs, which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen, three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal syst where antigen processing occurs, CD74 undergoes a sequential degradation by various proteases, including CTSS and CTSL, leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The roval of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell mbrane surface. In B-cells, the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal microenvironment has been implicated in the regulation of antigen loading into MHC II molecules, increased acidification produces increased proteolysis and efficient peptide loading.

NCBI and Uniprot Product Information

• NCBI GI #: 18426975
• NCBI GeneID: 3117
• NCBI Accession #: NP_002113.2
• NCBI GenBank Nucleotide #: NM_002122.3
• UniProt Accession #: P01909; O19630; O19706; P01907; P01908; P04225; P04226; P05536; P79553; Q06751; Q29876; Q29994
• Molecular Weight: 25.5kD
• NCBI Official Full Name: HLA class II histocompatibility antigen, DQ alpha 1 chain
• NCBI Official Synonym Full Names: major histocompatibility complex, class II, DQ alpha 1
• NCBI Official Symbol: HLA-DQA1
• NCBI Official Synonym Symbols: DQ-A1; CELIAC1; HLA-DQA
• NCBI Protein Information: HLA class II histocompatibility antigen, DQ alpha 1 chain
• UniProt Protein Name: HLA class II histocompatibility antigen, DQ alpha 1 chain
• Protein Family: HLA class II histocompatibility antigen
• UniProt Gene Name: HLA-DQA1

NCBI Description

HLA-DQA1 belongs to the HLA class II alpha chain paralogues. The class II molecule is a heterodimer consisting of an alpha (DQA) and a beta chain (DQB), both anchored in the membrane. It plays a central role in the immune system by presenting peptides derived from extracellular proteins. Class II molecules are expressed in antigen presenting cells (APC: B Lymphocytes, dendritic cells, macrophages). The alpha chain is approximately 33-35 kDa. It is encoded by 5 exons; exon 1 encodes the leader peptide, exons 2 and 3 encode the two extracellular domains, and exon 4 encodes the transmembrane domain and the cytoplasmic tail. Within the DQ molecule both the alpha chain and the beta chain contain the polymorphisms specifying the peptide binding specificities, resulting in up to four different molecules. Typing for these polymorphisms is routinely done for bone marrow transplantation. [provided by RefSeq, Jul 2008]

Uniprot Description

HLA-DQA1: Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route, where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules, and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments, exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides, autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs, other cells of the gastrointestinal tract, such as epithelial cells, express MHC class II molecules and CD74 and act as APCs, which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen, three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs, CD74 undergoes a sequential degradation by various proteases, including CTSS and CTSL, leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells, the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal microenvironment has been implicated in the regulation of antigen loading into MHC II molecules, increased acidification produces increased proteolysis and efficient peptide loading

Protein type: Cell surface; Membrane protein, integral

Chromosomal Location of Human Ortholog: 6p21.32

Cellular Component: Golgi membrane; lysosomal membrane; membrane; MHC class II protein complex; plasma membrane; trans-Golgi network membrane

Molecular Function: MHC class II receptor activity; peptide antigen binding

Biological Process: antigen processing and presentation of exogenous peptide antigen via MHC class II; T cell costimulation; T cell receptor signaling pathway