HYAL4
HYAL4 (hyaluronidase 4) is a membrane-associated member of the glycosyl hydrolase 56 family that cleaves chondroitin sulfate chains into smaller oligosaccharides. Its previous name was hyaluronoglucosaminidase 4, and it is one of the hyaluronidase gene group encoded in humans. Browse Assay Genie's current range of HYAL4 research reagents below, or read on for the biology behind the target.
HYAL4 is a glycosidase that acts on the glycosaminoglycan chains of the extracellular matrix. The NCBI Gene summary describes it as a chondroitin-sulfate-specific endo-beta-N-acetylgalactosaminidase, meaning it hydrolyses chondroitin sulfate chains and degrades them into oligosaccharides. UniProt reports the best substrate as the galactosaminidic linkage within a trisulfated tetrasaccharide, and also annotates the enzyme as an endo-hyaluronidase that breaks down hyaluronan into smaller oligosaccharide fragments. The two sources differ on this point: RefSeq states that the protein is similar in structure to the hyaluronidases but lacks hyaluronidase activity. Researchers working on substrate specificity should keep both descriptions in mind.
The HYAL4 gene belongs to the HGNC gene group Hyaluronidases and the glycosyl hydrolase 56 family, and the protein is annotated as a membrane protein with the EC number 3.2.1.35. Expression of the gene is highest in testes and placenta. The mouse ortholog is Hyal4. HYAL4 sits alongside HYAL1, HYAL2 and HYAL3 in this gene group, although the family members differ in how they are described in terms of substrate preference.
The biological context for chondroitin sulfate cleavage is the proteoglycan. Proteoglycans form when chondroitin sulfate chains link covalently to a core protein. They are ubiquitous components of the extracellular matrix of connective tissues and are also found at the surface of many cell types. There they take part in cell proliferation, differentiation, migration, cell-cell recognition, extracellular matrix deposition and tissue morphogenesis. By trimming chondroitin sulfate chains, HYAL4 is therefore relevant to how these matrix and cell-surface structures are remodelled. The related polymer hyaluronic acid is the substrate of other hyaluronidases in the group.
HYAL4 degrades chondroitin sulfate chains, making it relevant to studies of how connective tissue matrix components are turned over.
Proteoglycans carry chondroitin sulfate chains and influence proliferation, differentiation, migration and morphogenesis, so HYAL4 activity bears on these processes.
Sources differ on whether HYAL4 acts on hyaluronan, so it is a useful subject for defining hyaluronidase-family substrate specificity.
Expression of the HYAL4 gene is highest in testes and placenta, which makes these tissues a natural focus for functional studies.
HYAL4 is a chondroitin-sulfate-specific endo-beta-N-acetylgalactosaminidase that hydrolyses chondroitin sulfate chains into oligosaccharides. UniProt also annotates endo-hyaluronidase activity against hyaluronan, whereas the NCBI Gene summary states that it lacks hyaluronidase activity.
The HGNC-approved name is hyaluronidase 4, and the UniProt protein name is Hyaluronidase-4. The previous HGNC name was hyaluronoglucosaminidase 4. No alternative gene symbols are listed. The enzyme carries the EC number 3.2.1.35.
A mouse ortholog, Hyal4, is recorded for the human gene. HYAL4 belongs to the glycosyl hydrolase 56 family and the hyaluronidase gene group, alongside HYAL1, HYAL2 and HYAL3. Check the datasheet of any product for its validated reactivity.
Other hyaluronidase family members and the hyaluronan substrate, with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q2M3T9; product specifications from Assay Genie datasheets.