Stem Cell Related Patent Number US5585478

D4 gene and methods of use thereof

Lim, Bing; Dorchester, MA, USA
Lelias, Jean-Michel; Evry, France
Adra, Chaker N.; Boston, MA, USA
Ko, Jone L.; Sudbury, MA, USA

This invention describes a novel D4 protein preferentially expressed in hematopoietic cells, and the uses thereof. Described are the sequence, molecular structure and expression of a cDNA clone, denoted by D4, which is of human and murine origin and is preferentially expressed in hematopoietic cells. The human cDNA clone has been expressed in bacteria, the predicted 24 Kd protein has been purified, and the protein has since been used in studies of its biochemical function. As predicted on the basis of sequence, D4 can function as a GDP-dissociation inhibitor of at least several small GTP-binding proteins, such as CDC42 and rac. The D4 protein was used to generate a polyclonal antibody specific for the protein, and the human cDNA was used to obtain several full length murine genomic clones. A clone has been analyzed and sequenced for the construction of a gene-targeting vector to produce animals deficient in D4 through disruption of the gene by homologous recombination. Also provided are means by which these animals may be used as models for fundamental and applied research on the GTP-binding proteins. The isolated, purified D4 protein, which is encoded by a nucleic acid molecule expressed in mammalian hematopoietic cells, has a calculated molecular weight of approximately 23,000 daltons comprising in the carboxyl terminal region amino acids 169 to 197 of Seq. ID No. 4 or substitutions thereof which are present in naturally occurring D4 protein expressed in mammalian species. Recommendations are also provided for the therapeutic uses of such methods as a diagnostic tool, in research and for the treatment of leukemia tumors, as well as in bore marrow transplants. This invention represents an extension of other applications filed by the same assignee and inventors.

Application Number: Beth Israel Hospital Association, Boston, MA, USA

Date Filed: 08/18/94

Dated Published: 12/17/96

Assignee: Beth Israel Hospital Association, Boston, MA, USA