Alternative titles; symbols
HGNC Approved Gene Symbol: LIMK1
Cytogenetic location: 7q11.23 Genomic coordinates (GRCh38) : 7:74,083,804-74,122,525 (from NCBI)
There are numerous eukaryotic LIM proteins, so named for the LIM domains they contain. LIM domains are highly conserved cysteine-rich structures containing 2 zinc fingers (Mizuno et al., 1994). Although zinc fingers usually function by binding to DNA or RNA, the LIM motif probably mediates protein-protein interactions. LIM kinase-1 (LIMK1) belongs to a small subfamily with a unique combination of 2 N-terminal LIM motifs and a C-terminal protein kinase domain. These are linked by a proline-serine-rich region containing several putative casein kinase and map kinase recognition sites (Mizuno et al., 1994). LIMK1 lacks a signal peptide and putative transmembrane domains. Thus, it is likely to be a component of an intracellular signaling pathway and may be involved in brain development (Tassabehji et al., 1996).
Proschel et al. (1995) isolated the murine Limk1 gene. They found that the mouse Limk1 gene has 95% homology with human LIMK1, suggesting that their function is conserved. Proschel et al. (1995) showed that Limk1 is expressed in the central nervous system during embryogenesis, including the inner nuclear layer of the retina, the cortex, the developing spinal cord, and the cranial nerve and dorsal root ganglia. In adult mice, expression occurs in retina, cortex, and spinal cord.
Using a functional screen, Sotiropoulos et al. (1999) identified LIMK1 as a potent activator of serum response factor (SRF; 600589), which in turn regulates transcription of many serum-inducible and muscle-specific genes. They showed that SRF activation by LIMK1 is dependent on its ability to regulate actin treadmilling.
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.
Geneste et al. (2002) found that Limk and diaphanous (DIAPH1; 602121) cooperated to regulate Srf and actin dynamics in a rat neural precursor cell line.
By coimmunoprecipitation analysis of B16-F1 mouse melanoma cells, Lee et al. (2014) showed that full-length Lrap25 (FAM89B; 616128) interacted with the kinases Mrck (e.g., MRCKA, or CDC42BPA; 603412) and Limk1. Lrap25 functioned as an adaptor that localized Mrck to lamellipodium and tethered Mrck to Limk1. Knockdown and inhibitor studies revealed that Lrap25 and Mrck were required for Limk1-dependent phosphorylation of cofilin. Depletion of Lrap25 altered cell polarity and inhibited cell migration. Lee et al. (2014) concluded that LRAP25 and MRCK regulate cofilin phosphorylation and F-actin dynamics at the leading edge of migrating cells via activation of LIMK1.
Davila et al. (2003) found that LIMK1 was overexpressed in prostate tumors and in prostate cancer cell lines and that the concentration of phosphorylated cofilin was higher in metastatic prostate cancer cells. Partial reduction of LIMK1 with antisense LIMK1 arrested cells at G2/M, altered the morphology and organization of the actin cytoskeleton, and abolished the invasive behavior of prostate cancer cells, but it did not reduce phosphorylation of cofilin. Ectopic expression of LIMK1 promoted the acquisition of an invasive phenotype by benign prostate epithelial cells. Davila et al. (2003) hypothesized that LIMK1 overexpression may result from chromosomal gain on 7q11.2, which has been associated with metastatic prostate cancers.
In the mammalian nervous system, the spatiotemporal control of mRNA translation has an important role in synaptic development and plasticity. Schratt et al. (2006) demonstrated that a brain-specific microRNA, miR134 (610164), is localized to the synaptodendritic compartment of rat hippocampal neurons and negatively regulates the size of dendritic spines--postsynaptic sites of excitatory synaptic transmission. This effect was mediated by miR134 inhibition of the translation of an mRNA encoding a protein kinase, Limk1, that controls spine development. Exposure of neurons to extracellular stimuli such as brain-derived neurotrophic factor (BDNF; 113505) relieves miR134 inhibition of LIMK1 translation and in this way may contribute to synaptic development, maturation, and or plasticity.
Bernard et al. (1996) cloned and characterized the mouse gene encoding Kiz1/Limk1. The gene spans 25 kb and the organization of its 16 exons does not correlate with its functional domains.
Proschel et al. (1995) determined that mouse Limk1 is a single-copy gene located at the distal end of chromosome 5. They predicted that the human LIMK1 gene maps to chromosome 7q.
Bernard et al. (1996) localized the human LIMK1 gene by FISH to chromosome 17q25, whereas they found that the mouse gene lies on chromosome 5, band G2. The location of the human gene is in conflict with the prediction of Proschel et al. (1995), based on the murine mapping, that LIMK1 lies in the distal portion of 7q. Mao et al. (1996) used FISH to map LIMK1 to 7q11.23 and its mouse homolog to 5G1. They pointed to a paper by Okano et al. (1995) that also mapped the gene to 7q11.23.
Tassabehji et al. (1996) isolated a cosmid clone that contained the entire human LIMK1 gene and confirmed its map location as 7q11.23.
By FISH in 20 Williams-Beuren syndrome (WBS; 194050) patients hemizygous for the elastin gene (ELN; 130160), Tassabehji et al. (1996) showed that the patients also had 1 copy of LIMK1 deleted. PCR analysis of a somatic-cell hybrid containing the deleted chromosome 7 from a patient with WS confirmed that the entire LIMK1 gene was deleted. Tassabehji et al. (1996) noted that the LIMK1 and elastin genes lie close together: a single cosmid of approximately 36 kb contained both LIMK1 and the 3-prime region of the elastin gene. LIMK1 is a strong candidate for the unexplained neurologic features of Williams-Beuren syndrome.
To identify genes important for human cognitive development, Frangiskakis et al. (1996) studied WBS patients, who show poor visuospatial constructive cognition. They described 2 families with a partial WS phenotype; affected members had the specific WS cognitive profile and vascular disease, but lacked other WS features. Submicroscopic 7q11.23 deletions cosegregated with the phenotype in both families. DNA sequence analyses of the region affected by the smallest deletion (83.6 kb) revealed both the ELN gene and the LIMK1 gene. The latter is strongly expressed in the brain. Because ELN mutations cause vascular disease but not cognitive abnormalities, Frangiskakis et al. (1996) suggested that LIMK1 hemizygosity is implicated in the impaired visuospatial constructive cognition of Williams-Beuren syndrome.
Most individuals with Williams-Beuren syndrome have a 1.6-Mb deletion in chromosome 7q11.23 that encompasses the ELN gene, whereas most families with autosomal dominant supravalvar aortic stenosis (SVAS; 185500) have point mutations in ELN. The overlap of the clinical phenotypes of the 2 conditions (cardiovascular disease and connective tissue abnormalities such as hernias) is due to the effect of haploinsufficiency of ELN. To find other genes contributing to the Williams-Beuren syndrome phenotype, Morris et al. (2003) studied 5 families with SVAS who had small deletions in the WBS region. None of the families had mental retardation, but affected family members had the WBS cognitive profile. All families shared a deletion of LIMK1, supporting the hypothesis that LIMK1 hemizygosity contributes to impairment in visuospatial constructive cognition.
Using homologous recombination, Meng et al. (2002) generated Limk1 knockout mice. The mice exhibited significant abnormalities in spine morphology and synaptic function, including enhanced hippocampal long-term potentiation. In behavioral tests, the mice showed altered fear responses and spatial learning. Results of Western blot analysis and immunostaining indicated that Limk1 plays a role in vivo in regulating cofilin and the actin cytoskeleton. Meng et al. (2002) concluded that Limk1 plays a critical role in dendritic spine morphogenesis and brain function.
A paper by Roovers et al. (2003) on the function of LIMK was retracted because a review of the primary source data 'found that portions of the figures assembled by the lead author are not supported by the primary data.'
Bernard, O., Burkitt, V., Webb, G. C., Bottema, C. D. K., Nicholl, J., Sutherland, G. R., Matthew, P. Structure and chromosomal localization of the genomic locus encoding the Kiz1 LIM-kinase gene. Genomics 35: 593-596, 1996. [PubMed: 8812497] [Full Text: https://doi.org/10.1006/geno.1996.0403]
Davila, M., Frost, A. R., Grizzle, W. E., Chakrabarti, R. LIM kinase 1 is essential for the invasive growth of prostate epithelial cells: implications in prostate cancer. J. Biol. Chem. 278: 36868-36875, 2003. [PubMed: 12821664] [Full Text: https://doi.org/10.1074/jbc.M306196200]
Frangiskakis, J. M., Ewart, A. K., Morris, C. A., Mervis, C. B., Bertrand, J., Robinson, B. F., Klein, B. P., Ensing, G. J., Everett, L. A., Green, E. D., Proschel, C., Gutowski, N. J., Noble, M., Atkinson, D. L., Odelberg, S. J., Keating, M. T. LIM-kinase1 hemizygosity implicated in impaired visuospatial constructive cognition. Cell 86: 59-69, 1996. [PubMed: 8689688] [Full Text: https://doi.org/10.1016/s0092-8674(00)80077-x]
Geneste, O., Copeland, J. W., Treisman, R. LIM kinase and Diaphanous cooperate to regulate serum response factor and actin dynamics. J. Cell Biol. 157: 831-838, 2002. [PubMed: 12034774] [Full Text: https://doi.org/10.1083/jcb.200203126]
Lee, I. C. J., Leung, T., Tan, I. Adaptor protein LRAP25 mediates myotonic dystrophy kinase-related Cdc42-binding kinase (MRCK) regulation of LIMK1 protein in lamellipodial F-actin dynamics. J. Biol. Chem. 289: 26989-27003, 2014. [PubMed: 25107909] [Full Text: https://doi.org/10.1074/jbc.M114.588079]
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]
Mao, X., Jones, T. A., Williamson, J., Gutowski, N. J., Proschel, C., Noble, M., Sheer, D. Assignment of the human and mouse LIM-kinase genes (LIMK1; Limk1) to chromosome bands 7q11.23 and 5G1, respectively, by in situ hybridization. Cytogenet. Cell Genet. 74: 190-191, 1996. [PubMed: 8941371] [Full Text: https://doi.org/10.1159/000134411]
Meng, Y., Zhang, Y., Tregoubov, V., Janus, C., Cruz, L., Jackson, M., Lu, W.-Y., MacDonald, J. F., Wang, J. Y., Falls, D. L., Jia, Z. Abnormal spine morphology and enhanced LTP in LIMK-1 knockout mice. Neuron 35: 121-133, 2002. [PubMed: 12123613] [Full Text: https://doi.org/10.1016/s0896-6273(02)00758-4]
Mizuno, K., Okano, I., Ohashi, K., Nunoue, K., Kuma, K., Miyata, T., Nakamura, T. Identification of a human cDNA encoding a novel protein kinase with two repeats of the LIM/double zinc finger motif. Oncogene 9: 1605-1612, 1994. [PubMed: 8183554]
Morris, C. A., Mervis, C. B., Hobart, H. H., Gregg, R. G., Bertrand, J., Ensing, G. J., Sommer, A., Moore, C. A., Hopkin, R. J., Spallone, P. A., Keating, M. T., Osborne, L., Kimberley, K. W., Stock, A. D. GTF2I hemizygosity implicated in mental retardation in Williams syndrome: genotype-phenotype analysis of five families with deletions in the Williams syndrome region. Am. J. Med. Genet. 123A: 45-59, 2003. [PubMed: 14556246] [Full Text: https://doi.org/10.1002/ajmg.a.20496]
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]
Proschel, C., Blouin, M. J., Gutowski, N. J., Ludwig, R., Noble, M. Limk1 is predominantly expressed in neural tissues and phosphorylates serine, threonine and tyrosine residues in vitro. Oncogene 11: 1271-1281, 1995. [PubMed: 7478547]
Roovers, K., Klein, E. A., Castagnino, P., Assoian, R. K. Nuclear translocation of LIM kinase mediates Rho-Rho kinase regulation of cyclin D1 expression. Dev. Cell 5: 273-284, 2003. Note: Retraction: Dev. Cell 10: 681 only, 2006. [PubMed: 12919678] [Full Text: https://doi.org/10.1016/s1534-5807(03)00206-5]
Schratt, G. M., Tuebing, F., Nigh, E. A., Kane, C. G., Sabatini, M. E., Kiebler, M., Greenberg, M. E. A brain-specific microRNA regulates dendritic spine development. Nature 439: 283-289, 2006. Note: Erratum: Nature 441: 902 only, 2006. [PubMed: 16421561] [Full Text: https://doi.org/10.1038/nature04367]
Sotiropoulos, A., Gineitis, D., Copeland, J., Treisman, R. Signal-regulated activation of serum response factor is mediated by changes in actin dynamics. Cell 98: 159-169, 1999. [PubMed: 10428028] [Full Text: https://doi.org/10.1016/s0092-8674(00)81011-9]
Tassabehji, M., Metcalfe, K., Fergusson, W. D., Carette, M. J. A., Dore, J. K., Donnai, D., Read, A. P., Proschel, C., Gutowski, N. J., Mao, X., Sheer, D. LIM-kinase deleted in Williams syndrome. (Letter) Nature Genet. 13: 272-273, 1996. [PubMed: 8673124] [Full Text: https://doi.org/10.1038/ng0796-272]