MGAT4A

Description

The MGAT4A (alpha-1,3-mannosyl-glycoprotein 4-beta-N-acetylglucosaminyltransferase A) is a protein-coding gene located on chromosome 2.

MGAT4A is a type II membrane protein and an enzyme, specifically a glycosyltransferase, that participates in the transfer of N-acetylglucosamine (GlcNAc) to N-linked glycans in the Golgi apparatus. It works in conjunction with the related isoenzyme MGAT4B to form tri- and tetra-antennary sugar chains. MGAT4A is involved in glucose transport by modifying SLC2A2/GLUT2, a glucose transporter, and controlling its expression on the surface of pancreatic beta cells. Some research suggests that MGAT4A may also play a role in regulating serum glycoprotein levels, oncogenesis, and differentiation. The gene encoding MGAT4A was first identified by Yoshida and colleagues. The protein has three potential N-glycosylation sites and consists of 535 amino acids. Its structure is similar to other Golgi glycosyltransferases. The amino acid sequences of human and bovine MGAT4A are 95% identical. MGAT4A has been found in all human tissues and cell lines examined, including normal tissues and cancer cell lines. The relative expression levels of MGAT4A are similar across different tissues, but the mRNA expression levels vary considerably. The highest mRNA levels in normal tissues were found in the spleen, thymus, peripheral blood leukocytes, lymph nodes, prostate, pancreas, and small intestine. Among cancer cell lines, the promyelocytic leukemia cell line HL-60 and the lymphoblastic leukemia cell line MOLT-4 exhibited the highest expression levels. Studies have proposed that the MGAT4A isoenzyme might act as a switch in the development of type 2 diabetes.

MGAT4A is a glycosyltransferase that adds a GlcNAc sugar molecule to a specific branch of N-linked glycans. This process contributes to the formation of tri- and tetra-antennary N-linked sugar chains, which are important for protein structure and function. MGAT4A also plays a role in glucose transport by modifying the SLC2A2/GLUT2 protein, which controls the expression of this glucose transporter on the surface of pancreatic beta cells.

MGAT4A is also known as GNT-IV, GNT-IVA, GnT-4a.

Associated Diseases

WES Whole Exome Sequencing