TY - JOUR
T1 - A heteromorphic protein-tyrosine phosphatase, PTPφ, is regulated by CSF-1 in macrophages
AU - Pixley, Fiona J.
AU - Lee, Pierre S.W.
AU - Dominguez, Melissa G.
AU - Einstein, Douglas B.
AU - Stanley, E. Richard
PY - 1995/11/10
Y1 - 1995/11/10
N2 - A novel protein-tyrosine phosphatase, PTPφ, was cloned from a murine macrophage cDNA library. As a result of alternative splicing, macrophage PTPφ mRNAs are predicted to encode two membrane-spanning molecules and a cytosolic enzyme with identical catalytic domains. The membrane-spanning forms differ in the juxtamembrane region, while a start codon downstream of this region is utilized in the translation of the putative cytosolic form. Expression of PTPφ mRNA is low and restricted to macrophage cell lines, macrophage-rich tissues, and brain, kidney, and heart. The mRNA in macrophages and heart is ∼2.8 kilobases (kb). However, a ∼5.5-kb transcript in brain and kidney indicates a fourth isoform encoding a large extracellular domain. The ∼5.5-kb PTPφ brain mRNA encodes the mouse homolog of GLEPP1, a recently reported glomerular epithelial protein. The level of expression of the mRNA encoding the cytosolic form was very low, and only the membrane-spanning proteins (43 and 47 kDa) could be detected in macrophages. Following addition of colony stimulating factor-1 to quiescent BAC1.2F5 macrophages, PTPφ mRNA and protein were down-regulated. The restricted expression of the shorter isoforms of PTPφ and their regulation by colony stimulating factor-1 in macrophages suggest that PTPφ may play a role in mononuclear phagocyte survival, proliferation, and/or differentiation.
AB - A novel protein-tyrosine phosphatase, PTPφ, was cloned from a murine macrophage cDNA library. As a result of alternative splicing, macrophage PTPφ mRNAs are predicted to encode two membrane-spanning molecules and a cytosolic enzyme with identical catalytic domains. The membrane-spanning forms differ in the juxtamembrane region, while a start codon downstream of this region is utilized in the translation of the putative cytosolic form. Expression of PTPφ mRNA is low and restricted to macrophage cell lines, macrophage-rich tissues, and brain, kidney, and heart. The mRNA in macrophages and heart is ∼2.8 kilobases (kb). However, a ∼5.5-kb transcript in brain and kidney indicates a fourth isoform encoding a large extracellular domain. The ∼5.5-kb PTPφ brain mRNA encodes the mouse homolog of GLEPP1, a recently reported glomerular epithelial protein. The level of expression of the mRNA encoding the cytosolic form was very low, and only the membrane-spanning proteins (43 and 47 kDa) could be detected in macrophages. Following addition of colony stimulating factor-1 to quiescent BAC1.2F5 macrophages, PTPφ mRNA and protein were down-regulated. The restricted expression of the shorter isoforms of PTPφ and their regulation by colony stimulating factor-1 in macrophages suggest that PTPφ may play a role in mononuclear phagocyte survival, proliferation, and/or differentiation.
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U2 - 10.1074/jbc.270.45.27339
DO - 10.1074/jbc.270.45.27339
M3 - Article
C2 - 7592997
AN - SCOPUS:0028784299
SN - 0021-9258
VL - 270
SP - 27339
EP - 27347
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 45
ER -