Hyaluronidase-2 is a multifunctional protein, previously thought to only possess acid-active

hyaluronan Hyaluronic acid (; abbreviated HA; conjugate base hyaluronate), also called hyaluronan, is an anionic, nonsulfated glycosaminoglycan distributed widely throughout connective, epithelial, and neural tissues. It is unique among glycosaminoglyca ...

-degrading enzymatic function. In humans it is encoded by the ''HYAL2''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

. This gene encodes a protein which is similar in structure to hyaluronidases. Hyaluronidases intracellularly degrade

, one of the major

glycosaminoglycans Glycosaminoglycans (GAGs) or mucopolysaccharides are long, linear polysaccharides consisting of repeating disaccharide units (i.e. two-sugar units). The repeating two-sugar unit consists of a uronic sugar and an amino sugar, except in the case ...

of the extracellular matrix. Hyaluronan is thought to be involved in cell proliferation, migration and differentiation. Varying functions have been described for this protein. It has been described as a lysosomal hyaluronidase which is active at a pH below 4 and specifically hydrolyzes high molecular weight hyaluronan. It has also been described as a GPI-anchored cell surface protein which does not display hyaluronidase activity but does serve as a receptor for the

oncogenic Carcinogenesis, also called oncogenesis or tumorigenesis, is the formation of a cancer, whereby normal cells are transformed into cancer cells. The process is characterized by changes at the cellular, genetic, and epigenetic levels and abnor ...

virus Jaagsiekte sheep retrovirus. The gene is one of several related genes in a region of chromosome 3p21.3 associated with

tumor suppression A tumor suppressor gene (TSG), or anti-oncogene, is a gene that regulates a cell during cell division and replication. If the cell grows uncontrollably, it will result in cancer. When a tumor suppressor gene is mutated, it results in a loss or red ...

. This gene encodes two alternatively spliced transcript variants which differ only in the 5' UTR. One study found associations between

cleft lip and palate A cleft lip contains an opening in the upper lip that may extend into the nose. The opening may be on one side, both sides, or in the middle. A cleft palate occurs when the palate (the roof of the mouth) contains an opening into the nose. The ...

and mutations in the ''HYAL2'' gene. An investigation published in 2017, attributed an additional function to the Hyaluronidase 2 (HYAL2) protein. The study found interactions between HYAL2 and proteins involved in the

alternative splicing Alternative splicing, or alternative RNA splicing, or differential splicing, is an alternative splicing process during gene expression that allows a single gene to code for multiple proteins. In this process, particular exons of a gene may be i ...

of ''

CD44 The CD44 antigen is a cell-surface glycoprotein involved in cell–cell interactions, cell adhesion and migration. In humans, the CD44 antigen is encoded by the ''CD44'' gene on chromosome 11. CD44 has been referred to as HCAM (homing cell adhes ...

'' pre-mRNA. Another study published in 2020, described roles for HYAL2 in the orchestration of cytoskeletal components involved in myofibroblast contraction. These recent discoveries suggest a broader regulatory role for the HYAL2 protein in cell biology.

References

Further reading