Leukocyte receptor tyrosine kinase explained

Leukocyte receptor tyrosine kinase is an enzyme that in humans is encoded by the LTK gene.^{[1] [2]}

Function

The protein encoded by this gene is a member of the ALK/LTK receptor family of receptor tyrosine kinases (RTKs) whose ligand is unknown.^[3] Closely related to the insulin receptor family of RTKs. Tyrosine-specific phosphorylation of proteins is a key to the control of diverse pathways leading to cell growth and differentiation. Two alternatively spliced transcript variants encoding different isoforms have been described for this gene.^[2]

Interactions

LTK has been shown to interact with IRS-1, Shc, and PIK3R1.^{[4] [5]}

Further reading

• Krolewski JJ, Dalla-Favera R . The ltk gene encodes a novel receptor-type protein tyrosine kinase. . EMBO J. . 10 . 10 . 2911–9 . 1991 . 10.1002/j.1460-2075.1991.tb07841.x . 1655406 . 453005 .
• Krolewski JJ, Lee R, Eddy R, Shows TB, Dalla-Favera R . Identification and chromosomal mapping of new human tyrosine kinase genes. . Oncogene . 5 . 3 . 277–82 . 1990 . 2156206 .
• Ben-Neriah Y, Bauskin AR . Leukocytes express a novel gene encoding a putative transmembrane protein-kinase devoid of an extracellular domain. . Nature . 333 . 6174 . 672–6 . 1988 . 2836739 . 10.1038/333672a0 . 1988Natur.333..672B . 4262549 .
• Toyoshima H, Kozutsumi H, Maru Y, Hagiwara K, Furuya A, Mioh H, Hanai N, Takaku F, Yazaki Y, Hirai H . Differently spliced cDNAs of human leukocyte tyrosine kinase receptor tyrosine kinase predict receptor proteins with and without a tyrosine kinase domain and a soluble receptor protein. . Proc. Natl. Acad. Sci. U.S.A. . 90 . 12 . 5404–8 . 1993 . 7685902 . 46728 . 10.1073/pnas.90.12.5404 . 1993PNAS...90.5404T . free .
• Richard I, Broux O, Chiannilkulchai N, Fougerousse F, Allamand V, Bourg N, Brenguier L, Devaud C, Pasturaud P, Roudaut C . Regional localization of human chromosome 15 loci. . Genomics . 23 . 3 . 619–27 . 1995 . 7851890 . 10.1006/geno.1994.1550 .
• Kozutsumi H, Toyoshima H, Hagiwara K, Yazaki Y, Hirai H . Human ltk receptor tyrosine kinase binds to PLC-gamma 1, PI3-K, GAP and Raf-1 in vivo. . Oncogene . 9 . 10 . 2991–8 . 1994 . 8084603 .
• Kozutsumi H, Toyoshima H, Hagiwara K, Furuya A, Mioh H, Hanai N, Yazaki Y, Hirai H . Identification of the human ltk gene product in placenta and hematopoietic cell lines. . Biochem. Biophys. Res. Commun. . 190 . 2 . 674–9 . 1993 . 8427607 . 10.1006/bbrc.1993.1101 .
• Ueno H, Sasaki K, Kozutsumi H, Miyagawa K, Mitani K, Yazaki Y, Hirai H . Growth and survival signals transmitted via two distinct NPXY motifs within leukocyte tyrosine kinase, an insulin receptor-related tyrosine kinase. . J. Biol. Chem. . 271 . 44 . 27707–14 . 1996 . 8910363 . 10.1074/jbc.271.44.27707 . free .
• Snijders AJ, Ho SC, Haase VH, Pillai S, Bernards A . A lymphocyte-specific Ltk tyrosine kinase isoform is retained in the endoplasmic reticulum in association with calnexin. . J. Biol. Chem. . 272 . 2 . 1297–301 . 1997 . 8995435 . 10.1074/jbc.272.2.1297 . free .
• Ueno H, Honda H, Nakamoto T, Yamagata T, Sasaki K, Miyagawa K, Mitani K, Yazaki Y, Hirai H . The phosphatidylinositol 3' kinase pathway is required for the survival signal of leukocyte tyrosine kinase. . Oncogene . 14 . 25 . 3067–72 . 1997 . 9223670 . 10.1038/sj.onc.1201153 . free .
• Espanel X, Huguenin-Reggiani M, Hooft van Huijsduijnen R . The SPOT technique as a tool for studying protein tyrosine phosphatase substrate specificities. . Protein Sci. . 11 . 10 . 2326–34 . 2003 . 12237455 . 2373693 . 10.1110/ps.0213402 .
• Li N, Nakamura K, Jiang Y, Tsurui H, Matsuoka S, Abe M, Ohtsuji M, Nishimura H, Kato K, Kawai T, Atsumi T, Koike T, Shirai T, Ueno H, Hirose S . Gain-of-function polymorphism in mouse and human Ltk: implications for the pathogenesis of systemic lupus erythematosus. . Hum. Mol. Genet. . 13 . 2 . 171–9 . 2004 . 14695357 . 10.1093/hmg/ddh020 . free .

Notes and References

1. Maru Y, Hirai H, Takaku F . Human ltk: gene structure and preferential expression in human leukemic cells . Oncogene Res . 5 . 3 . 199–204 . May 1990 . 2320375 .
2. Web site: Entrez Gene: LTK leukocyte tyrosine kinase.
3. Lopes SS, Yang X, Müller J, Carney TJ, McAdow AR, Rauch GJ, Jacoby AS, Hurst LD, Delfino-Machín M, Haffter P, Geisler R, Johnson SL, Ward A, Kelsh RN . Leukocyte tyrosine kinase functions in pigment cell development . PLOS Genet. . 4 . 3 . e1000026 . 2008 . 18369445 . 2265441 . 10.1371/journal.pgen.1000026 . free .
4. Kozutsumi H, Toyoshima H, Hagiwara K, Yazaki Y, Hirai H . Human ltk receptor tyrosine kinase binds to PLC-gamma 1, PI3-K, GAP and Raf-1 in vivo . Oncogene . 9 . 10 . 2991–8 . October 1994 . 8084603 .
5. Ueno H, Honda H, Nakamoto T, Yamagata T, Sasaki K, Miyagawa K, Mitani K, Yazaki Y, Hirai H . The phosphatidylinositol 3' kinase pathway is required for the survival signal of leukocyte tyrosine kinase . Oncogene . 14 . 25 . 3067–72 . June 1997 . 9223670 . 10.1038/sj.onc.1201153 . free .