MAMMALIAN SIALYLTRANSFERASES

Information

  • Research Project
  • 2175027
  • ApplicationId
    2175027
  • Core Project Number
    R01GM027904
  • Full Project Number
    5R01GM027904-16
  • Serial Number
    27904
  • FOA Number
  • Sub Project Id
  • Project Start Date
    8/1/1990 - 34 years ago
  • Project End Date
    3/31/1997 - 27 years ago
  • Program Officer Name
  • Budget Start Date
    4/1/1994 - 30 years ago
  • Budget End Date
    3/31/1995 - 29 years ago
  • Fiscal Year
    1994
  • Support Year
    16
  • Suffix
  • Award Notice Date
    3/29/1994 - 30 years ago
Organizations

MAMMALIAN SIALYLTRANSFERASES

In the past project period cDNAs were cloned for two additional sialyltransferases, the Galbeta1,3GalNAc alpha2,3 sialyltransferase and the Galbeta1,3/4GlcNAc alpha2,3 sialyltransferase. Comparison of the coding sequences with that of the Galbeta1,4GlcNAc alpha2,6 sialyltransferase revealed a unique pattern of homology among glycosyltransferase families. There was a 55 residue stretch of high homology in the center of each enzyme (40-60% identity) with no detectable homology between any of the enzymes outside that region. We have termed this conserved region the sialylmotif. In the next project period several aims pertain to this conserved motif. 1) Additional members of the 10-12 member sialyltransferase family will be cloned using a PCR homology approach using the information contained in the sialylmotif. Preliminary efforts using this approach have been successful in pulling out another cDNA from embryonic brain that has the sialylmotif and other sequence features like the three sialyltransferases cloned to date. A 'soluble form' of this putative enzyme will be constructed and expressed to evaluate the activity and specificity in order to identify which enzyme has been cloned. Other sialyltransferase cDNAs obtained by this approach will be evaluated similarly. 2) The sialylmotif will be investigated for its functional properties by a site- directed mutagenesis expression approach. The driving force for this investigation stems from the successful crystallization of the Galbeta1,4GlcNAc alpha2,6 sialyltransferase by the group of Dr. Don Wiley at Harvard. Thus, the results regarding function will likely be interpretable from the three dimensional structure of the enzyme in the foreseeable future. Several other specific aims take advantage of the new tools resulting from the cloned sialyltransferases. 1) The long time collaboration with Dr. Jurgen Roth for localization of sialyltransferases will be extended to the newly cloned enzymes. 2) The newly expressed enzymes will be used to develop a flexible and practical route to the combined chemical and enzymatic synthesis of sialosides. 3) One of the three cloned sialyltransferases appears to be responsible for the conversion of peanut agglutinin positive (PNA+) T-cells to the PNA- phenotype during maturation in the thymus. In collaboration with Dr. Steve Hedrick and Dr. Ajit Varki at UCSD, transgenic mice are being constructed to test the function of this glycosylation change.

IC Name
NATIONAL INSTITUTE OF GENERAL MEDICAL SCIENCES
  • Activity
    R01
  • Administering IC
    GM
  • Application Type
    5
  • Direct Cost Amount
  • Indirect Cost Amount
  • Total Cost
  • Sub Project Total Cost
  • ARRA Funded
  • CFDA Code
    863
  • Ed Inst. Type
  • Funding ICs
  • Funding Mechanism
  • Study Section
    PC
  • Study Section Name
    Physiological Chemistry Study Section
  • Organization Name
    CYTEL CORPORATION
  • Organization Department
  • Organization DUNS
  • Organization City
    SAN DIEGO
  • Organization State
    CA
  • Organization Country
    UNITED STATES
  • Organization Zip Code
    92121
  • Organization District
    UNITED STATES