The Golgi complex form catalyzes the production of lactose in the lactating mammary gland and could also be responsible for the synthesis of complex-type N-linked oligosaccharides in many glycoproteins as well as the carbohydrate moieties of glycolipids. The cell surface form functions as a recognition molecule during a variety of cell to cell and cell to matrix interactions, as those occurring during development and egg fertilization, by binding to specific oligosaccharide ligands on opposing cells or in the extracellular matrix.
Ubiquitously expressed, but at very low levels in fetal and adult brain.
Protein modification; protein glycosylation.
Involvement in disease
Defects in B4GALT1 are the cause of congenital disorder of glycosylation type 2D (CDG2D) [MIM:607091]. CDGs are a family of severe inherited diseases caused by a defect in protein N-glycosylation. They are characterized by under-glycosylated serum proteins. These multisystem disorders present with a wide variety of clinical features, such as disorders of the nervous system development, psychomotor retardation, dysmorphic features, hypotonia, coagulation disorders, and immunodeficiency. The broad spectrum of features reflects the critical role of N-glycoproteins during embryonic development, differentiation, and maintenance of cell functions.
Belongs to the glycosyltransferase 7 family.
The soluble form derives from the membrane forms by proteolytic processing.
Golgi apparatus > Golgi stack membrane. Cell membrane. Cell surface. Found in trans cisternae of Golgi; Golgi apparatus > Golgi stack membrane. Found in trans cisternae of Golgi and Secreted. Soluble form found in body fluids.