HGNC Approved Gene Symbol: LIMK2
Cytogenetic location: 22q12.2 Genomic coordinates (GRCh38): 22:31,212,298-31,280,080 (from NCBI)
Okano et al. (1995) isolated a human cDNA encoding LIMK2, a second member of the LIMK family, with a domain structure similar to LIMK1 (601329) and 50% overall amino acid identity with LIMK1. They also identified 2 alternative transcripts, LIMK2a and LIMK2b, which are probably due to variation in transcription initiation. By Northern blot analysis, a 3.7-kb LIMK2 mRNA was detected in all tissues tested, with the highest level in placenta and a moderate level in liver, lung, kidney, and pancreas, whereas a 1.6-kb LIMK2 mRNA was detected only in skeletal muscle and heart. The 3.7-kb transcript was detected in lung, stomach, and renal cancer cell lines.
Osada et al. (1996) found that LIMK2a transcripts were more abundant than LIMK2b in liver, colon, stomach, and spleen, whereas LIMK2b transcripts were more abundant in brain, kidney, and placenta. The former encodes a protein containing 2 LIM domains, a PDZ domain, and a kinase domain, whereas the latter has only 1.5 LIM domains. Transfection studies showed an association of 63-kD and 58-kD proteins with the LIMK2a and LIMK2b proteins. The former is distributed in the cytoplasm and nucleus and the latter occurs mainly in the cytoplasm. A truncated LIMK2-kinase has a nuclear location, not showing the protein association.
Okano et al. (1995) demonstrated a serine/threonine-specific kinase activity of LIMK1 and LIMK2 by in vitro analysis.
Maekawa et al. (1999) demonstrated that LIM kinase is phosphorylated and activated by ROCK (601702), a downstream effector of Rho, and that LIM kinase, in turn, phosphorylates cofilin (601442), inhibiting its actin-depolymerizing activity. They concluded that this pathway contributes to Rho-induced reorganization of the actin cytoskeleton.
Okano et al. (1995) mapped the LIMK2 gene to chromosome 22q12 by fluorescence in situ hybridization.
Maekawa, M., Ishizaki, T., Boku, S., Watanabe, N., Fujita, A., Iwamatsu, A., Obinata, T., Ohashi, K., Mizuno, K., Narumiya, S. Signaling from Rho to the actin cytoskeleton through protein kinases ROCK and LIM-kinase. Science 285: 895-898, 1999. [PubMed: 10436159] [Full Text: https://doi.org/10.1126/science.285.5429.895]
Okano, I., Hiraoka, J., Otera, H., Nunoue, K., Ohashi, K., Iwashita, S., Hirai, M., Mizuno, K. Identification and characterization of a novel family of serine/threonine kinases containing two N-terminal LIM motifs. J. Biol. Chem. 270: 31321-31330, 1995. [PubMed: 8537403] [Full Text: https://doi.org/10.1074/jbc.270.52.31321]
Osada, H., Hasada, K., Inazawa, J., Uchida, K., Ueda, R., Takahashi, T., Takahashi, T. Subcellular localization and protein interaction of the human LIMK2 gene expressing alternative transcripts with tissue-specific regulation. Biochem. Biophys. Res. Commun. 229: 582-589, 1996. [PubMed: 8954941] [Full Text: https://doi.org/10.1006/bbrc.1996.1847]