Has1

Hyaluronan or hyaluronic acid (HA) is a high molecular weight unbranched polysaccharide synthesized by a wide variety of organisms from bacteria to mammals, and is a constituent of the extracellular matrix. It consists of alternating glucuronic acid and N-acetylglucosamine residues that are linked by beta-1-3 and beta-1-4 glycosidic bonds. HA is synthesized by membrane-bound synthase at the inner surface of the plasma membrane, and the chains are extruded through pore-like structures into the extracellular space. It serves a variety of functions, including space filling, lubrication of joints, and provision of a matrix through which cells can migrate. HA is actively produced during wound healing and tissue repair to provide a framework for ingrowth of blood vessels and fibroblasts. Changes in the serum concentration of HA are associated with inflammatory and degenerative arthropathies such as rheumatoid arthritis. In addition, the interaction of HA with the leukocyte receptor CD44 is important in tissue-specific homing by leukocytes, and overexpression of HA receptors has been correlated with tumor metastasis. HAS1 is a member of the newly identified vertebrate gene family encoding putative hyaluronan synthases, and its amino acid sequence shows significant homology to the hasA gene product of Streptococcus pyogenes, a glycosaminoglycan synthetase (DG42) from Xenopus laevis, and a recently described murine hyaluronan synthase. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2014]

Hyaluronan Synthase 1

Catalyzes the addition of GlcNAc or GlcUA monosaccharides to the nascent hyaluronan polymer. Therefore, it is essential to hyaluronan synthesis a major component of most extracellular matrices that has a structural role in tissues architectures and regulates cell adhesion, migration and differentiation. This is one of the isozymes catalyzing that reaction. Also able to catalyze the synthesis of chito-oligosaccharide depending on the substrate (By similarity).

Cell adhesion Source: ProtInc
Cellular response to platelet-derived growth factor stimulus Source: UniProtKB
Extracellular matrix assembly Source: UniProtKB
Extracellular polysaccharide biosynthetic process Source: UniProtKB
Glycosaminoglycan biosynthetic process Source: ProtInc
Hyaluronan biosynthetic process Source: GO_Central
Negative regulation of fibroblast migration Source: UniProtKB

Membrane

Cytoplasmic: 1-25
Helical: 26-46
Extracellular: 47-52
Helical: 53-73
Cytoplasmic: 74-399
Helical: 400-420
Extracellular: 421-430
Helical: 431-451
Cytoplasmic: 452-457
Helical: 458-478
Extracellular: 479-497
Helical: 498-518
Cytoplasmic: 519-540
Helical: 541-561
Extracellular: 562-578