title: LIM kinase 1, a key regulator of actin dynamics, is widely expressed in embryonic and adult tissues.
abstract: The expression of endogenous LIM kinase 1 (LIMK1) protein was investigated in embryonic and adult mice using a rat monoclonal antibody (mAb), which recognizes specifically the PDZ domain of LIMK1 and not LIMK2. Immunoblotting analysis revealed widespread expression of LIMK1 existing as a 70-kDa protein in tissues and in cell lines, with a higher mass form (approximately 75 kDa) present in some tissues and cell lines. Smaller isoforms of approximately 50 kDa were also occasionally evident. Immunofluorescence analysis demonstrated LIMK1 subcellular localization at focal adhesions in fibroblasts as revealed by co-staining with actin, paxillin and vinculin in addition to perinuclear (Golgi) and occasional nuclear localization. Furthermore, an association between LIMK1 and paxillin but not vinculin was identified by co-immunoprecipitation analysis. LIMK1 is enriched in both axonal and dendritic growth cones of E18 rat hippocampal pyramidal neurons where it is found in punctae that extend far out into filopodia, as well as in a perinuclear region identified as Golgi. In situ, we identify LIMK1 protein expression in all embryonic and adult tissues examined, albeit at different levels and in different cell populations. The rat monoclonal LIMK1 antibody recognizes proteins of similar size in cell and tissue extracts from numerous species. Thus, LIMK1 is a widely expressed protein that exists as several isoforms.
authors.affiliation: Molecular Genetics of Cancer Division, The Walter and Eliza Hall Institute of Medical Research, PO The Royal Melbourne Hospital, Melbourne, Victoria 3050, Australia.
authors.forename: Victoria C
authors.initials: VC
authors.lastname: Foletta
authors.forename: Nathalie
authors.initials: N
authors.lastname: Moussi
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Sarmiere
authors.forename: James R
authors.initials: JR
authors.lastname: Bamburg
authors.forename: Ora
authors.initials: O
authors.lastname: Bernard
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D000911:Antibodies, Monoclonal; D019556:COS Cells; D002454:Cell Differentiation / Q000502:physiology*; D002642:Chick Embryo; D003598:Cytoskeletal Proteins / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000166:cytology / Q000201:enzymology*; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D022001:Focal Adhesions / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D006801:Humans; D054461:Lim Kinases; D051379:Mice; D008810:Mice, Inbred C57BL; D008970:Molecular Weight; D041681:NIH 3T3 Cells; D016501:Neurites / Q000378:metabolism; D009928:Organ Specificity; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism; D020033:Protein Isoforms / Q000378:metabolism; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary / Q000502:physiology; D011554:Pseudopodia / Q000378:metabolism; D051381:Rats
chemical_list: D000199:Actins; D000911:Antibodies, Monoclonal; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; D020033:Protein Isoforms; C496062:Pxn protein, mouse; C496063:Pxn protein, rat; D011494:Protein Kinases; C515892:LIMK1 protein, human; C102895:LIMK2 protein, human; D054461:Lim Kinases; C515893:Limk1 protein, mouse; C515894:Limk1 protein, rat; C095325:Limk2 protein, mouse; C490644:Limk2 protein, rat; D017346:Protein Serine-Threonine Kinases