Cloned (Comment) | Organism |
---|---|
gene CSGALNACT1 or t1, quantitative RT-PCR enzyme expression analysis of CS glycosyltransferases | Mus musculus |
gene CSGALNACT2 or t2, quantitative RT-PCR enzyme expression analysis of CS glycosyltransferases | Mus musculus |
Protein Variants | Comment | Organism |
---|---|---|
additional information | generation of single knockout T1 KO mutant and of double knockout mutant Col2-DKO, a chondrocyte-specific t1::t2 KO mutant, quantitative RT-PCR analysis of knee cartilage shows no or slight t1 and t2 gene expression in Col2-DKO mice compared with wild-type mice. t1::t2 double KO mice show severe dwarfism and postnatal lethality, pgenotype, overview | Mus musculus |
additional information | generation of single knockout T2 KO mutant and of double knockout mutant Col2-DKO, a chondrocyte-specific t1::t2 KO mutant, quantitative RT-PCR analysis of knee cartilage shows no or slight t1 and t2 gene expression in Col2-DKO mice compared with wild-type mice. t1::t2 double KO mice show severe dwarfism and postnatal lethality, phenotype, overview | Mus musculus |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
cell membrane | - |
Mus musculus | - |
- |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
UDP-N-acetyl-D-galactosamine + beta-D-glucuronyl-(1->3)-D-galactosyl-proteoglycan | Mus musculus | - |
UDP + N-acetyl-D-galactosaminyl-(1->4)-beta-D-glucuronyl-(1->3)-beta-D-galactosyl-proteoglycan | - |
? | |
UDP-N-acetyl-D-galactosamine + beta-D-glucuronyl-(1->3)-D-galactosyl-proteoglycan | Mus musculus C57BL/6 | - |
UDP + N-acetyl-D-galactosaminyl-(1->4)-beta-D-glucuronyl-(1->3)-beta-D-galactosyl-proteoglycan | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Mus musculus | Q8BJQ9 | gene t1 | - |
Mus musculus | Q8C1F4 | gene t2 | - |
Mus musculus C57BL/6 | Q8BJQ9 | gene t1 | - |
Mus musculus C57BL/6 | Q8C1F4 | gene t2 | - |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
bone | quantitative gene expression and in situ hybridization of genes associated with endochondral ossification | Mus musculus | - |
cartilage | knee, quantitative RT-PCR enzyme expression analysis of CSGALNACT1 | Mus musculus | - |
cartilage | knee, quantitative RT-PCR enzyme expression analysis of CSGALNACT2 | Mus musculus | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
UDP-N-acetyl-D-galactosamine + beta-D-glucuronyl-(1->3)-D-galactosyl-proteoglycan | - |
Mus musculus | UDP + N-acetyl-D-galactosaminyl-(1->4)-beta-D-glucuronyl-(1->3)-beta-D-galactosyl-proteoglycan | - |
? | |
UDP-N-acetyl-D-galactosamine + beta-D-glucuronyl-(1->3)-D-galactosyl-proteoglycan | - |
Mus musculus C57BL/6 | UDP + N-acetyl-D-galactosaminyl-(1->4)-beta-D-glucuronyl-(1->3)-beta-D-galactosyl-proteoglycan | - |
? |
Synonyms | Comment | Organism |
---|---|---|
chondroitin sulfate N-acetylgalactosaminyltransferase 1 | - |
Mus musculus |
chondroitin sulfate N-acetylgalactosaminyltransferase 2 | - |
Mus musculus |
CSGalNAcT1 | - |
Mus musculus |
CSGALNACT2 | - |
Mus musculus |
General Information | Comment | Organism |
---|---|---|
malfunction | impaired chndroitin sulfate (CS) content in cartilage and induction of abnormal endochondral ossification is caused by t1::t2 (CSGALNACT1/CSGALNACT2) double deficiency. DKO mice exhibit postnatal lethality, whereas t2 KO mice show normal size and skeletal development. Col2-DKO mice survive to adulthood and show severe dwarfism. Histological analysis of epiphyseal cartilage from Col2-DKO mice reveals disrupted endochondral ossification, characterized by drastic GAG reduction in the extracellular matrix. DKO cartilage has reduced chondrocyte proliferation and an increased number of apoptotic chondrocytes compared with wild-type cartilage. Conversely, primary chondrocyte cultures from Col2-DKO knee cartilage have the same proliferation rate as wild-type chondrocytes and low GAG expression levels, indicating that the chondrocytes themselves have an intact proliferative ability. Quantitative RT-PCR analysis of E18.5 cartilage shows that the expression levels of Col2a1 and Ptch1 transcripts tend to decrease in DKO compared with those in wild-type mice. Phenotype of t2 null mice, overview | Mus musculus |
malfunction | t1 single knockout mice (t1 KO) exhibit slight dwarfism and a reduction in chondroitin sulfate (CS) content in cartilage compared with wild-type mice. Impaired chondroitin sulfate (CS) content in cartilage and induction of abnormal endochondral ossification is caused by t1::t2 (CSGALNACT1/CSGALNACT2) double deficiency. DKO mice exhibit postnatal lethality. Col2-DKO mice survive to adulthood and show severe dwarfism compared with t1 KO mice. Histological analysis of epiphyseal cartilage from Col2-DKO mice reveals disrupted endochondral ossification, characterized by drastic GAG reduction in the extracellular matrix. DKO cartilage has reduced chondrocyte proliferation and an increased number of apoptotic chondrocytes compared with wild-type cartilage. Conversely, primary chondrocyte cultures from Col2-DKO knee cartilage have the same proliferation rate as wild-type chondrocytes and low GAG expression levels, indicating that the chondrocytes themselves have an intact proliferative ability. Quantitative RT-PCR analysis of E18.5 cartilage shows that the expression levels of Col2a1 and Ptch1 transcripts tend to decrease in DKO compared with those in wild-type mice. The CS content in DKO cartilage is decreased compared with that in t1 KO cartilage | Mus musculus |
metabolism | six glycosyltransferases are known to coordinately synthesize the backbone structure of chondroitin sulfate (CS). Two glycosyltransferases, Csgalnact1 (t1) and Csgalnact2 (t2), are critical for initiation of CS synthesis in vitro. According to an in vitro enzymatic characterization, among the six CS glycosyltransferases, only t1 and t2 possessed the ability to independently initiate CS synthesis. t1 efficiently transfers GalNAc onto the linkage tetrasaccharide in vitro, which is common to both CS and heparin sulfate/heparin, and t1 initiation activity is stronger than that of t2 | Mus musculus |
additional information | quantitative analysis of six CS glycosyltransferase transcripts using real-time RT-PCR | Mus musculus |
physiological function | both chondroitin sulfate N-acetylgalactosaminyltransferase 1 (t1) and chondroitin sulfate N-acetylgalactosaminyltransferase 2 (t2) are necessary for chondroitin sulfate (CS) synthesis and normal chondrocyte differentiation but are not sufficient for all CS synthesis in cartilage. CS biosynthesis is initiated by the transfer of GalNAc residues to the linkage region, which consists of tetrasaccharide units of GlcUA-beta1,3-galactose (Gal)-beta1,3-Gal-beta1,4-xylose (Xyl) attached to the serine residues of the core proteins. This triggers CS elongation by alternating addition of GalNAc and GlcUA residues, which is catalyzed by six glycosyltransferases in mammals. Enzyme t1 and t2 are known to function in both initiation and elongation activity. t1 exhibits stronger initiation activity than t2, indicating that t1 has a vital role in CS synthesis initiation | Mus musculus |
physiological function | both chondroitin sulfate N-acetylgalactosaminyltransferase 1 (t1) and chondroitin sulfate N-acetylgalactosaminyltransferase 2 (t2) are necessary for chondroitin sulfate (CS) synthesis and normal chondrocyte differentiation but are not sufficient for all CS synthesis in cartilage. CS biosynthesis is initiated by the transfer of GalNAc residues to the linkage region, which consists of tetrasaccharide units of GlcUA-beta1,3-galactose (Gal)-beta1,3-Gal-beta1,4-xylose (Xyl) attached to the serine residues of the core proteins. This triggers CS elongation by alternating addition of GalNAc and GlcUA residues, which is catalyzed by six glycosyltransferases in mammals. t1 and t2 are known to function in both initiation and elongation activity. Enzyme t1 exhibits stronger initiation activity than t2, indicating that t1 has a vital role in CS synthesis initiation | Mus musculus |