Xenopus LIM motif-containing protein kinase, Xlimk1, is expressed in the developing head structure of the embryo.
The LIM double zinc finger motif locates in several developmentally functioning and cytoskeletal proteins, and is considered to act as a specific motif for protein-protein interactions. LIM kinase (LIMK) is a novel protein kinase containing two LIM motifs at the N-terminal, the function of which has yet to be clearly defined. In this study, we cloned a cDNA encoding Xenopus counterpart of human LIMK1 gene by RT-PCR mediated cloning, and designated in Xlimk1. Xlimk1 is highly homologous to mammalian LIMK1 in each structural domain, particularly in LIM and protein kinase domains. In Northern blot analysis, two distinct Xlimk1 transcripts of 9.0 Kb and 3.7 Kb were present in early cleavage stages of the embryo. Both mRNA species were subsequently decreased at the gastrula stages. The 9.0 Kb of Xlimk1 mRNA again appeared in late neurula stage, then the expression level gradually increased in later stages of the embryo. Whole-mount in situ hybridization analysis showed the localization of Xlimk1 transcripts in the animal half of the blastula embryo. In post-neurula stages, specific signals for Xlimk1 were predominant in the anterior (head) region of the embryo, including developing brain, hyoid and branchial arches, and anlagen of sensory organs. These results indicate that Xlimk1 may play an important role in neural development and formation of anterior (head) structures in the Xenopus embryo.
Takahashi
T
T
Department of Oncology, Osaka University Medical School, Japan.
Aoki
S
S
Nakamura
T
T
Koshimizu
U
U
Matsumoto
K
K
Nakamura
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D006257:Head / Q000196:embryology*; D006801:Humans; D054461:Lim Kinases; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D011487:Protein Conformation; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D014158:Transcription, Genetic; D014981:Xenopus; D016335:Zinc Fingers
D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D011494:Protein Kinases; C515892:LIMK1 protein, human; D054461:Lim Kinases; D017346:Protein Serine-Threonine Kinases