Lineage- and differentiation stage-specific expression of LSM-1 (LPAP), a possible substrate for CD45, in human hematopoietic cells.
CD45, a transmembrane tyrosine phosphatase, is found on almost all nucleated hematopoietic cells and plays a crucial role in lymphocyte activation and differentiation. We recently achieved isolation of the human LSM-1 (hLSM-1) gene, whose product is a possible substrate for CD45, and we raised antibodies against the hLSM-1 protein. hLSM-1 expression in hematopoietic cells was examined with Northern and Western blot, fluorescence-activated cell sorter, and immunocytochemical analyses. It was found that in the lymphoid lineage, T and B lymphocytes as well as NK cells expressed LSM-1, whereas terminally differentiated plasma cells did not. As for the myeloid lineage, immature myeloid cells expressed LSM-1, whereas terminally differentiated granulocytes and monocytes did not. In the erythroid lineage, normal erythroblasts expressed very low levels of LSM-1, while erythroid cell lines (K562 and HEL) did not. Megakaryocytes did not express LSM-1. Both CD34+/CD33- and CD34+/CD33+ hematopoietic progenitor cells weakly expressed LSM-1. These results showed that LSM-1 is expressed in a lineage- and differentiation stage-specific fashion.
Shimizu
Y
Y
Department of Medicine III, Osaka University Medical School, Japan.
Sugiyama
H
H
Fujii
Y
Y
Sasaki
K
K
Inoue
K
K
Ogawa
H
H
Tamaki
H
H
Miyake
S
S
Oji
Y
Y
Soma
T
T
Yamagami
T
T
Hirata
M
M
Ikeda
K
K
Monden
T
T
Kishimoto
T
T
D015153:Blotting, Western; D002454:Cell Differentiation; D002455:Cell Division; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004900:Erythroblasts / Q000502:physiology; D005434:Flow Cytometry; D015870:Gene Expression; D006098:Granulocytes / Q000502:physiology; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000502:physiology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009000:Monocytes / Q000502:physiology; D010750:Phosphoproteins; D012333:RNA, Messenger / Q000235:genetics; D014018:Tissue Distribution
D018076:DNA, Complementary; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C090519:PTPRCAP protein, human; D010750:Phosphoproteins; D012333:RNA, Messenger