ASPH

ASPH stands for aspartyl/asparaginyl beta-hydroxylase, a human gene that encodes an iron(II)/2-oxoglutarate-dependent dioxygenase enzyme. The enzyme catalyzes the hydroxylation of the beta-carbon of aspartate and asparagine residues within epidermal growth factor-like repeats of various proteins, including Notch receptors and related signaling molecules.

Biochemically, ASPH is classified as a 2-oxoglutarate-dependent dioxygenase. It requires iron and 2-oxoglutarate as cofactors and functions within secretory pathway compartments such as the endoplasmic reticulum to modify substrate proteins after they are synthesized. This post-translational modification can influence the maturation, stability, and signaling properties of target proteins, particularly those involved in cell communication and development.

Expression of ASPH is developmentally regulated and detected across multiple tissues. In cancer biology, however, ASPH is often found at elevated levels in tumors such as hepatocellular carcinoma, pancreatic cancer, and colorectal cancer. Higher ASPH expression has been associated with increased invasive potential, metastasis, and, in some studies, poorer patient prognosis. Because of these associations, ASPH has attracted interest as a potential biomarker and as a therapeutic target. Preclinical work has explored approaches to inhibit ASPH enzymatic activity or to reduce its expression, with the aim of dampening Notch-related signaling and tumor progression.

ASPH is commonly referred to simply as aspartyl/asparaginyl beta-hydroxylase. It is part of the broader family of 2-oxoglutarate-dependent dioxygenases and contributes to understanding how post-translational modifications of EGF-like repeats influence development and disease.