Disease relevance of CHSY1

• The interaction between SStp, the transit peptide of the precursor protein to the small subunit of Rubisco (prSSU) and two Hsp70 molecular chaperones, Escherichia coli DnaK and pea (Pisum sativum) CSS1, was investigated in detail [1].

High impact information on CHSY1

• Activation of Notch2 was down-regulated by CHSY1 siRNA treatment [2].
• Modulating Notch signaling by CHSY1 via its DDD motif provides new insight into mechanisms of the interactions between myeloma cells and their bone marrow microenvironment [2].
• And interestingly, Fringe domain in CHSY1 has this DDD motif [2].
• RNA interference experiments with CHSY1 small interfering RNA (siRNA) reduced the amount of CHSY1 in the co-culture conditioned medium, and this was associated with a 6.25-fold increase in apoptotic myeloma cells over control co-cultures [2].
• Here, we show that when myeloma plasma cells are co-cultured with osteoclasts, chondroitin synthase 1 (CHSY1) is the most significantly altered soluble, secreted protein present in the conditioned medium [2].

Biological context of CHSY1

• We report here a novel human gene (GenBank trade mark accession number AB086062) that possesses a sequence homologous with the human chondroitin sulfate synthase-1 (CSS1) gene, formerly known as chondroitin synthase [3].

Associations of CHSY1 with chemical compounds

• We recently cloned human chondroitin synthase (ChSy) exhibiting the glucuronyltransferase-II (GlcATII) and N-acetylgalactosaminyltransferase-II (GalNAcTII) activities responsible for the biosynthesis of repeating disaccharide units of chondroitin sulfate, but chondroitin polymerization was not demonstrated in vitro using the recombinant ChSy [4].

Other interactions of CHSY1

• However, the specific activity of CSS3 was much lower than that of CSS1 [3].
• Both glucuronyltransferase and N-acetylgalactosaminyltransferase activities were observed when chondroitin, CS polymer, and their corresponding oligosaccharides were used as the acceptor substrates, but no polymerization reaction was observed as in the case of CSS1 [3].

Analytical, diagnostic and therapeutic context of CHSY1

• Quantitative real time PCR analysis revealed that the transcript level of CSS3 was much lower than that of CSS1, although it was ubiquitously expressed in various human tissues [3].

References