InnateDB: Systems Biology of the Innate Immune Response

Homo sapiens Protein: HMHA1

Summary

InnateDB Protein

IDBP-13716.6

Last Modified

2014-10-13 [Report errors or provide feedback]

Gene Symbol

HMHA1

Protein Name

histocompatibility (minor) HA-1

Synonyms

ARHGAP45; HA-1; HLA-HA1;

Species

Homo sapiens

Ensembl Protein

ENSP00000316772

InnateDB Gene

IDBG-13714 (HMHA1)

Protein Structure

UniProt Annotation

Function

GTPase activator for the Rho-type GTPases. {ECO:0000305}.Precursor of the histocompatibility antigen HA-1. More generally, minor histocompatibility antigens (mHags) refer to immunogenic peptide which, when complexed with MHC, can generate an immune response after recognition by specific T-cells. The peptides are derived from polymorphic intracellular proteins, which are cleaved by normal pathways of antigen processing. The binding of these peptides to MHC class I or class II molecules and its expression on the cell surface can stimulate T-cell responses and thereby trigger graft rejection or graft-versus-host disease (GVHD) after hematopoietic stem cell transplantation from HLA- identical sibling donor. GVHD is a frequent complication after bone marrow transplantation (BMT), due to mismatch of minor histocompatibility antigen in HLA-matched sibling marrow transplants. Specifically, mismatching for mHag HA-1 which is recognized as immunodominant, is shown to be associated with the development of severe GVHD after HLA-identical BMT. HA-1 is presented to the cell surface by MHC class I HLA-A*0201, but also by other HLA-A alleles. This complex specifically elicits donor- cytotoxic T-lymphocyte (CTL) reactivity against hematologic malignancies after treatment by HLA-identical allogenic BMT. It induces cell recognition and lysis by CTL. {ECO:0000269PubMed:12601144, ECO:0000269PubMed:8260714, ECO:0000269PubMed:8532022, ECO:0000269PubMed:9798702}.

Subcellular Localization

Disease Associations

Tissue Specificity

Expressed on cells of the hematopoietic lineage. Detected in dendritic cells and epidermal Langerhans cells. Expressed in peripheral blood mononuclear cells, in all leukemia/lymphoma cell lines. Detected also in some solid tumors and tissues such as cancerous and non-cancerous tissue. {ECO:0000269PubMed:11965046, ECO:0000269PubMed:8843592}.

Comments

Interactions

Number of Interactions

This gene and/or its encoded proteins are associated with 3 experimentally validated interaction(s) in this database.

Experimentally validated
Total	3 [view]
Protein-Protein	3 [view]
Protein-DNA	0
Protein-RNA	0
DNA-DNA	0
RNA-RNA	0
DNA-RNA	0

Gene Ontology

Molecular Function

Accession	GO Term
GO:0005096	GTPase activator activity
GO:0046872	metal ion binding

Biological Process

GO:0007165	signal transduction
GO:0007264	small GTPase mediated signal transduction
GO:0035556	intracellular signal transduction
GO:0043547	positive regulation of GTPase activity
GO:0051056	regulation of small GTPase mediated signal transduction

Cellular Component

GO:0005622	intracellular
GO:0005829	cytosol
GO:0016020	membrane

Protein Structure and Domains

PDB ID

InterPro

IPR000198 Rho GTPase-activating protein domain
IPR001060 FCH domain
IPR002219 Protein kinase C-like, phorbol ester/diacylglycerol-binding domain
IPR008936 Rho GTPase activation protein

PFAM

PF00620
PF00611
PF00130

PRINTS

PIRSF

SMART

SM00324
SM00055
SM00109

TIGRFAMs

Post-translational Modifications

Modification

Cross-References

SwissProt

Q92619