Alternative titles; symbols
HGNC Approved Gene Symbol: LAPTM5
Cytogenetic location: 1p35.2 Genomic coordinates (GRCh38): 1:30,732,469-30,757,774 (from NCBI)
Adra et al. (1996) used subtractive hybridization to clone a gene, designated p29 or LAPTM5 by them, whose expression was higher in adult hematopoietic cells than in nonhematopoietic cells. The predicted 262-amino acid human protein is 82% identical to the mouse protein and contains 5 highly hydrophobic transmembrane domains. An antibody raised to the protein was used to show that it colocalizes with the lysosomal proteins LAMP1 (153330), LAMP2 (309060), and CD63 (155740). Western blot analysis with cell fractions from rat spleen also suggested that LAPTM5 is lysosomal. Northern blot analysis detected a 2.3-kb transcript in hematopoietic cell lines and in normal bone marrow, spleen, thymus, lymph nodes, and peripheral blood leukocytes. It was also detected in lung, where it was especially prevalent. Western blots showed an expected 29-kD protein in hematopoietic cell lines. Embryonic expression was studied using the mouse cDNA and, in contrast to adults, transcription was seen in all embryonic tissues at about equal levels.
Scott et al. (1996) cloned mouse Laptm5, which they designated E3, and using this clone to screen a human HL60 cDNA library, they obtained human E3. The deduced mouse and human proteins contain 261 and 262 amino acids, respectively, and share 80% sequence identity. Mouse E3 has a series of strongly hydrophobic domains, 2 N-myristoylation sites, and 6 potential phosphorylation sites. Northern blot analysis of 11 mouse tissues detected highest E3 expression in bone marrow and spleen, with much weaker expression in thymus. In mouse cell lines, E3 expression was limited to cells of myeloid, erythroid, and B-lymphoid lineages.
Scott et al. (1996) found that expression of E3 was elevated following retinoic acid-induced differentiation of mouse promyelocytic cells toward myeloid lineage. Erythroid differentiation was associated with reduced E3 expression.
Adra et al. (1996) mapped the human LAPTM5 gene to chromosome 1p34 by fluorescence in situ hybridization.
Adra, C. N., Zhu, S., Ko, J.-L., Guillemot, J.-C., Cuervo, A. M., Kobayashi, H., Horiuchi, T., Lelias, J.-M., Rowley, J. D., Lim, B. LAPTM5: a novel lysosomal-associated multispanning membrane protein preferentially expressed in hematopoietic cells. Genomics 35: 328-337, 1996. [PubMed: 8661146] [Full Text: https://doi.org/10.1006/geno.1996.0364]
Scott, L. M., Mueller, L., Collins, S. J. E3, a hematopoietic-specific transcript directly regulated by the retinoic acid receptor alpha. Blood 88: 2517-2530, 1996. [PubMed: 8839844]