Low molecular weight protein tyrosine phosphtases, including the human red cell phosphatase, HCPTP, are widely expressed cytosolic proteins of approximately 18kDa that exist in distinct isoforms and are highly selective for phosphotyrosine over phosphoserine or phosphotyrosine. The HCPTP-A and HCPTP-B proteins expressed in human red cells and placenta are fast and slow forms of red cell acid phosphatase5. Like other tyrosine phosphatases, HCPTP is sensitive to inhibition by vanadate, and has a catalytic mechanism that involves formation of a cystinyl-phosphate intermediate6. The crystal structure of the bovine heart derived enzyme BHPTP shows a four-stranded central parallel b sheet with flanking a helices and an active site cysteine residue in the typical tyrosine phosphatase sequence context, CXXXXXR._x000B__x000B_Biological actions and cellular substrates have not been fully elucidated. It is expressed in a wide range of cell types, and structural homologues are expressed in yeast. A catalytically inactive LMW-PTP functions to promote cell division and binds to tyrosine-phosphorylated PDGF receptors1. The HCPTPA isoform interacts with receptor tyrosine kinases, EphB1 and VEGFR2 (flk-1)2,4. Its overexpression inhibits VEGF-induced endothelial proliferation and migration, and its recruitment to EphB1 complexes is crucial to downstream signaling between EphB1 and integrins that mediate cell-matrix attachment3.

Loss of chromosome 10q is a frequently observed genetic defect in prostate cancer. Recently, the PTEN/MMAC1 tumor suppressor gene was identified and mapped to chromosome 10q23.3. PTEN is often found mutated in various cancers. The high frequency (60%) of PTEN mutations and deletions found in prostate cancer samples indicates a significant role of this tumor suppressor gene in the pathogenesis of prostate cancer. PTEN mRNA expression was clearly observed in all cell lines and xenografts without large homozygous deletions, showing that PTEN downregulation is not an important mechanism of PTEN inactivation. The immunogen used was a GST-pTEN fusion protein a.a. seq. 188-403.

Axol's anti-human Psoriasin antibody detects psoriasin by both western blot and on formalin and paraffin fixed tissue sections. The staining on tissue sections is both nuclear and cytoplasmic. Although its expression in breast cancer is downregulated (in both preinvasive and invasive cancers) when its expression is maintained in breast cancer the expression of psoriasin is correlated with estrogen receptor negativity and node positivity and therefore with poor prognostic features. Further it is correlated with the degree of inflammation inthe tumor which is consistent with its being a chemotactic factor.

This antibody reacts with a glycoprotein of 200 kDa present in proximal renal tubules. The antigen is a carbohydrate in nature and retained in formalin fixed paraffin embedded tissues. Other normal tissues that display the antigen include breast, parathyroid glands and epididymis. Among renal carcinomas, 93% of primary and 84% of metastatic carcinomas are positive for this antigen. Relatively few other tumor types are positive: breast cancers, teratocarcinomas and parathyroid adenomas.

The immunogen used to generate the purified antibody was a PP X/C peptide conjugated to KLH corresponding to the sequence. This peptide antibody corresponds to the internal sequence of PP X/C.

The immunogen used to generate the purified antibody was a PP X/C peptide conjugated to KLH corresponding to the sequence aa 294-307

The immunogen used to generate the purified antibody was a peptide conjugated to KLH corresponding to the sequence NH2-Cys-Ala-Val-Pro-Asp-Ser-Glu-Arg-Val-IlePro-Pro-Arg-Thr-Thr-Thr-Pro-Tyr-COOH. This peptide antibody corresponds to C -terminal peptide of PPV catalytic subunit having a MW of 33kDa.

The immunogen used to generate the purified antibody was a peptide conjugated to KLH corresponding to the sequence NH2-Cys-Ala-Val-Pro-Asp-Ser-Glu-Arg-Val-IlePro-Pro-Arg-Thr-Thr-Thr-Pro-Tyr-COOH. This peptide antibody corresponds to C -terminal peptide of PPV catalytic subunit having a MW of 33kDa.

Protein phosphatase 5 (PP5) is a novel human protein serine/threonine phosphatase of molecular weight of 58 kDa. It is made up of a C-terminal phosphatase catalytic domain and an N-terminal domain, which has four repeats of 34 amino acids, three of which are tandemly arranged. The phosphatase domain contains all of the invariant motifs of the PP1/PP2A/PP2B gene family. However, it is not closely related to any other known member of this family of phosphatases. Thus it makes up a new subfamily of phosphatases. PP5 expressed in bacteria has been shown to dephosphorylate serine residues in proteins and is more sensitive than PP1 to the tumor promoter okadaic acid. PP5 appears to be localized to the nucleus suggesting that, like other nuclear tetratricopeptide (TPR)-containing proteins, it may playa role in the regulation of RNA biogenesis and mitosis.

Protein serine/threonine phosphatase 4R1 is a protein which is associated with the catalytic subunit of protein serine/threonine phosphatase 4 (PP4C) and may possibly regulate the activity of the enzyme. PP4C is 65% identical to PP2AC at the amino acid level and has been placed in the type 2A family of phosphatases. PP4C has been highly conserved between species sharing 91% amino acid identity between human and Drosophila PP4C is predominantly localized in the nucleus in rat brain and liver but is most highly expressed in testis. Additionally, PP4C was demonstrated to be an essential enzyme in the development of Drosophila embryos. The expression of PP4C was reduced to 25% of the normal protein level in a mutant strain of Drosophila termed centrosomes minus microtubules (cmm). An interesting characteristic of the cmm phenotype is the presence of regions of cells that are unable to complete mitosis because no microtubules exist to connect chromatin and centrosomes. This phenotype implicates PP4C in the regulation of the nucleation and/or stabilization of microtubules. These data taken together indicate that PP4 has a crucial cellular function, although a physiological substrate for PP4 has not yet been identified.

Protein serine/threonine phosphatase 4R1 is a protein which is associated with the catalytic subunit of protein serine/threonine phosphatase 4 (PP4C) and may possibly regulate the activity of the enzyme. PP4C is 65% identical to PP2AC at the amino acid level and has been placed in the type 2A family of phosphatases. PP4C has been highly conserved between species sharing 91% amino acid identity between human and Drosophila PP4C is predominantly localized in the nucleus in rat brain and liver but is most highly expressed in testis. Additionally, PP4C was demonstrated to be an essential enzyme in the development of Drosophila embryos. The expression of PP4C was reduced to 25% of the normal protein level in a mutant strain of Drosophila termed centrosomes minus microtubules (cmm). An interesting characteristic of the cmm phenotype is the presence of regions of cells that are unable to complete mitosis because no microtubules exist to connect chromatin and centrosomes. This phenotype implicates PP4C in the regulation of the nucleation and/or stabilization of microtubules. These data taken together indicate that PP4 has a crucial cellular function, although a physiological substrate for PP4 has not yet been identified.

The immunogen is the purified peptide conjugated to KLH.

The immunogen is the purified peptide conjugated to KLH.

The immunogen used for the anti-protein phosphatase 2B was a purified peptide conjugated to KLH. The sequence of the peptide is NH2-Arg-Met-Pro-Pro-Arg-Arg-Asp-Ala-Met-Pro-Ser-Asp-Ala-C00H (a.a. 268-280) corresponding to a 60kDa protein

The immunogen used for the anti-protein phosphatase 2B was a purified peptide conjugated to KLH. The sequence of the peptide is NH2-Arg-Met-Pro-Pro-Arg-Arg-Asp-Ala-Met-Pro-Ser-Asp-Ala-COOH (a.a. 482-494) corresponding to a 60kDa protein

The immunogen used to generate the purified antibody was a peptide conjugated to KLH corresponding to the sequence NH2-Pro-His-Val-Thr-Arg-Arg-Thr-Pro-Asp-Tyr-Phe-Leu-COOH. This peptide antibody corresponds to C -terminal peptide of PP2A/C catalytic subunit having a MW of 36kDa. The sequence used is amino acid 298-309.

Protein phosphatase 2A (PP2A) is a hetertrimeric enzyme consisting of a catalytic subunits (C), a structural subunit (A) and a variable regulatory subunit (B). The B subunit family is made up of the , and isoforms. The PP2A/B isoform appears to only be detectable in the brain where it has been speculated that it cytoskeletal substrates. The RNA which produces the PP2A/B is developmentally regulated and increases sharply after birth. It has also been suggested that it may be important in the establishment and maintenance of neuronal connections.

PP2A is a heterotrimeric phosphatase, ccomposed of A, B and C subunits. The structural A and catalytic C subunits form the constitutive core of the enzyme, which associates with one of a large number of regulatory B subunits. Three families of B subunits have been identified thus far. The prototypical B (or PR55) family of subunits is encoded by three genes, B , B and B . The B' (or B56) family consists of at least seven splice variants derived from five genes. RNA's for the two members of the B'' family, PR72 and PR130, arise by alternative splicing or use of alternate transcription start sites from the same gene. Primary structures as well as functions of B and B' subunits are conserved from yeast to mammals. _x000B__x000B_B is a novel isoform of the B class of PP2A regulatory subunits. It is widely expressed in rat tissues and appears to be involved in targeting PP2A to the cytosolic compartment.

The immunogen used to generate the purified antibody was a peptide conjugated to KLH corresponding to the sequence NH2-Cys-Gly-Glu-Glu-Asp-Ile-Asp-THr-ArgLys-Ile-Asn-Asn-Ser-Phe-COOH. This peptide antibody corresponds to N terminal peptide of PP2A/B regulatory subunit having a MW of 53kDa. The sequence used is amino acid 2-14.

The immunogen used to generate the purified antibody was a peptide conjugated to KLH corresponding to the sequence NH2-Phe-Ser-Gln-Val-Lys-Gly-Ala-Val-AspAsp-Asp-Val-Ala-Glu-COOH. This peptide antibody corresponds to N -terminal peptide of PP2A/B regulatory subunit having a MW of 55kD. The sequence used is amino acid 14-27.