Abstract
Subtractive hybridisation was used to select for genes which are differentially expressed between a highly metastatic human colon carcinoma cell line, KM12SM, and the isogenetic non-metastatic cell line, KM12C. This led to the isolation of cDNA clones for a novel human adenosine 5′-phosphosulphate kinase/ATP sulphurylase (PAPS synthetase). Northern hybridisation revealed a single 4.2 kb mRNA species which showed an approximately 20-fold higher level of expression in the non-metastatic cell line than in the metastatic cell line. The overlapping cDNA clones together covered 3,774 bp including the entire coding region of 1,842 bp encoding a protein of 614 amino acids (calculated molecular mass of 69,496 Da). The protein contains consensus sequences for APS kinase and ATP sulphurylase, in its amino- and carboxy-terminal regions, respectively, as well as other sequences that are highly conserved amongst ATP sulphurylases and APS kinases. Interestingly, consensus sequences for GTPase activity were also identified, indicating that enzyme activity may be regulated by an intrinsic GTPase mechanism. Overall the new protein is 78% homologous with a previously described human PAPS synthetase (PAPSS1) indicating that we have identified the second member of a gene family which we have provisionally named PAPSS2. The gene locus for PAPSS2 was identified on chromosome 10 at 10q23.1–q23.2. This locus has synteny with the mouse brachymorphic gene recently identified as a PAPS synthetase (SK2). PAPSS2 appears to be the human homologue of this gene and thus PAPSS2 is likely to be important in human skeletogenesis.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: International Journal of Biochemistry and Cell Biology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.