ANTXR2 Gene

The ANTXR2 gene (ANTXR stands for anthrax cell adhesion molecule 2) is a protein-coding gene located on chromosome 4q21.21.

The ANTXR2 gene encodes a receptor for anthrax toxin. The receptor protein binds to collagen IV and laminin, suggesting that it may be involved in extracellular matrix adhesion. Several transcript variants encoding different isoforms have been found for this gene.

Mutations in this gene cause the

• juvenile hyaline fibromatosis

and

• infantile systemic hyalinosis (a particularly severe variant of juvenile hyaline fibromatosis.

ANTXR cell adhesion molecule 2 is necessary for cellular interactions with laminin and the extracellular matrix. It functions as a receptor for the protective antigen (PA) of B.anthracis. Binding of the microbial protein PA leads to heptamerization of the receptor-PA complex. Upon binding of the PA of B.anthracis, the complex moves to glycosphingolipid-rich lipid rafts, where it is internalized via a clathrin-dependent pathway. In the endosomal membrane, the complex rearranges at a pH below 7 and forms a pore through which the other components of anthrax toxin can escape into the cytoplasm.

1. Casas-Alba D et al (2018) Hyaline fibromatosis syndrome: Clinical update and phenotype-genotype correlations. Hum Mutat 39:1752-1763.
2. Chaudhry C et al (2021) Novel variation in ANTXR2 gene causing hyaline fibromatosis syndrome: A report from India. Congenit Anom (Kyoto) 61:140-141.
3. Härter B et al. (2020) Clinical aspects of hyaline fibromatosis syndrome and identification of a novel mutation. Mol Genet Genomic Med 8: e1203.