Chemistry: molecular biology and microbiology – Enzyme – proenzyme; compositions thereof; process for... – Hydrolase
Reexamination Certificate
2000-11-01
2002-07-16
Achutamurthy, Ponnathapu (Department: 1652)
Chemistry: molecular biology and microbiology
Enzyme , proenzyme; compositions thereof; process for...
Hydrolase
C435S252300, C435S320100, C435S325000, C536S023200, C536S023100, C536S024100
Reexamination Certificate
active
06420153
ABSTRACT:
BACKGROUND OF THE INVENTION
The intracellular phosphorylation of proteins is critical for a plethora of regulatory and signalling mechanisms in eukaryotic cells. Phosphorylation events can govern a wide range of cellular processes, including cell proliferation, differentiation, transcription, and morphology. Serine/threonine protein kinases, also called serine protein kinases, are frequently utilized in signalling cascades as the activity of these enzymes can be finely regulated by stimuli. A common stimulus is phosphorylation of the serine protein kinase itself. Hence, signalling pathways, such as the MAP protein kinase cascade and the JAK/STAT pathway, can contain multiple proteins kinases which are sequentially activated. Ultimately, kinase cascades can result in the phosphorylation of cytoskeletal proteins, transcription factors, and biosynthetic enzymes. Another class of kinases includes the receptor tyrosine kinases. Activated receptor tyrosine kinases not only autophosphorylate, but phosphorylate other intracellular signalling molecules, including those specifically bound to autophosphorylated receptors.
An essential component of the aforementioned signalling pathways is the ability of the cell to desensitize, recycle, and counteract phosphorylation signals. The cell primarily utilizes enzymes, termed phosphatases, which remove the phosphate on tyrosine, serine, and threonine side chains. Dual specificity phosphatases hydrolyze phosphotyrosine, phosphothreonine, and phosphoserine residues (for a review, see, e.g., Fauman and Saper (1996)
Trends in Biochem.
21:412). This class of proteins is exemplified by the VH1 or vaccinia virus late H1 gene protein, whose catalytic activity is required for vaccinia virus replication. A human homolog of VH1, VHR, has also been identified. VH1-like dual specificity phosphatase can also include the phosphatases PAC-1 and CL100/MKP-1, hVH-2/MKP-2, hVH-3, MKP-3, MKP-X, MKP-4, hVH-5, and M3/6 proteins. The PAC-1 and CL100 proteins hydrolyze phosphothreonine and phosphotyrosine residues on phosphorylated MAP (mitogen activated protein) kinases. In order to modulate signalling events, the activity and expression of dual specificity phosphatases can be finely regulated. For example, the PAC-1 and CL100 phosphatase can be induced by growth factors (Keyse, S (1995)
Biochim. Biophys. Acta
1265:152-160).
Thus, the function of dual specificity phosphatase proteins can be critical for the regulation of cellular processes such as proliferation and differentiation. Given the important biological roles and properties of such phosphatases, there exists a need for the identification of novel genes encoding such proteins as well as for the discovery of modulators of such molecules for use in regulating a variety of normal and/or pathological cellular processes.
SUMMARY OF THE INVENTION
The present invention is based, in part, on the discovery of a novel dual specificity phosphatase, referred to herein as “18232” nucleic acid and protein molecules. The nucleotide sequence of a cDNA encoding 18232 is shown in SEQ ID NO:1, and the amino acid sequence of a 18232 polypeptide is shown in SEQ ID NO:2. In addition, the nucleotide sequence of the coding region is depicted in SEQ ID NO:3.
Accordingly, in one aspect, the invention features a nucleic acid molecule that encodes a 18232 protein or polypeptide, e.g., a biologically active portion of the 18232 protein. In a preferred embodiment, the isolated nucleic acid molecule encodes a polypeptide having the amino acid sequence of SEQ ID NO:2. In other embodiments, the invention provides isolated 18232 nucleic acid molecules having the nucleotide sequence shown in SEQ ID NO:1 or SEQ ID NO:3. In still other embodiments, the invention provides nucleic acid molecules that are substantially identical (e.g., naturally occurring allelic variants) to the nucleotide sequence shown in SEQ ID NO:1 or SEQ ID NO:3. In other embodiments, the invention provides a nucleic acid molecule that hybridizes under stringent hybridization conditions to a nucleic acid molecule comprising the nucleotide sequence of SEQ ID NO:1 or 3, wherein the nucleic acid encodes a full length 18232 protein or an active fragment thereof.
In a related aspect, the invention further provides nucleic acid constructs that include a 18232 nucleic acid molecule described herein. In certain embodiments, the nucleic acid molecules of the invention are operatively linked to native or heterologous regulatory sequences. Also included are vectors and host cells containing the 18232 nucleic acid molecules of the invention, e.g., vectors and host cells suitable for producing 18232 nucleic acid molecules and polypeptides.
In another related aspect, the invention provides nucleic acid fragments suitable as primers or hybridization probes for the detection of 18232-encoding nucleic acids.
In still another related aspect, isolated nucleic acid molecules that are antisense to a 18232 encoding nucleic acid molecule are provided.
In another aspect, the invention features 18232 polypeptides and biologically active or antigenic fragments thereof that are useful, e.g., as reagents or targets in assays applicable to treatment and diagnosis of 18232-mediated or related disorders. In another embodiment, the invention provides 18232 polypeptides having a 18232 activity. Preferred polypeptides are 18232 proteins including at least one dual specificity phosphatase catalytic domain, and, preferably, having a 18232 activity, e.g., a 18232 activity as described herein.
In other embodiments, the invention provides 18232 polypeptides, e.g., a 18232 polypeptide having the amino acid sequence shown in SEQ ID NO:2; an amino acid sequence that is substantially identical to the amino acid sequence shown in SEQ ID NO:2; or an amino acid sequence encoded by a nucleic acid molecule having a nucleotide sequence that hybridizes under stringent hybridization conditions to a nucleic acid molecule comprising the nucleotide sequence of SEQ ID NO:1 or 3, wherein the nucleic acid encodes a full length 18232 protein or an active fragment thereof.
In a related aspect, the invention provides 18232 polypeptides or fragments operatively linked to non-18232 polypeptides to form fusion proteins.
In another aspect, the invention features antibodies and antigen-binding fragments thereof, that react with, or more preferably specifically bind 18232 polypeptides.
In another aspect, the invention provides methods of screening for compounds that modulate the expression or activity of the 18232 polypeptides or nucleic acids.
In still another aspect, the invention provides a process for modulating 18232 polypeptide or nucleic acid expression or activity, e.g. using the screened compounds. In certain embodiments, the methods involve treatment of conditions related to decreased activity or expression of the 18232 polypeptides or nucleic acids, such as conditions involving aberrant cellular proliferation of a 18232 expressing cell, e.g., a hematopoietic cell (e.g., an erythroid cell (e.g., an erythrocyte or an erythroblast), a CD34 positive cell, a glycophorin A-expressing cell, a megakaryocyte). The condition may involve increased hematopoietic cell activity or proliferation as in the case of leukemia, e.g., an erythroleukemia; or decreased hematopoietic cell differentiation as in the case of, e.g., an anemia.
In still another aspect, the invention features a method of modulating (e.g., enhancing or inhibiting) the proliferation, survival, and/or differentiation of a cell, e.g., a 18232-expressing cell, e.g., a hematopoietic cell (e.g., an erythroid cell, a bone marrow cell such as a CD34 positive cell, a megakaryocyte). The method includes contacting the cell with an agent that modulates the activity or expression of a 18232 polypeptide or nucleic acid, in an amount effective to modulate the proliferation and/or differentiation of the cell.
In a preferred embodiment, the 18232 polypeptide has an amino acid sequence identical to, or substantially identical to, SEQ ID NO:2. In other embodiments, the 18232 polypeptide is
Meyers Rachel A.
Weich Nadine
Achutamurthy Ponnathapu
Fish & Richardson P.C.
Millennium Pharmaceuticals Inc.
Pak Yong
LandOfFree
18232, a novel dual specificity phosphatase and uses therefor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with 18232, a novel dual specificity phosphatase and uses therefor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and 18232, a novel dual specificity phosphatase and uses therefor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2825028