title: Cloning of three novel neuronal Cdk5 activator binding proteins.
abstract: Neuronal Cdc2-like kinase (Nclk) is involved in the regulation of neuronal differentiation and neuro-cytoskeleton dynamics. The active kinase consists of a catalytic subunit, Cdk5, and a 25 kDa activator protein (p25nck5a) derived from a 35 kDa neuronal-specific protein (p35nck5a). As an extension of our previous study (Qi, Z., Tang, D., Zhu, X., Fujita, D.J., Wang, J.H., 1998. Association of neurofilament proteins with neuronal Cdk5 activator. J. Biol. Chem. 270, 2329-2335), which showed that neurofilament is one of the p35nck5a-associated proteins, we now report the isolation of three other novel p35nck5a-associated proteins using the yeast two-hybrid screen. The full-length forms of these three novel proteins, designated C42, C48 and C53, have a molecular mass of 66, 24, and 57 kDa, respectively. Northern analysis indicates that these novel proteins are widely expressed in human tissues, including the heart, brain, skeletal muscle, placenta, lung, liver, kidney and pancreas. The bacterially expressed glutathione S-transferase (GST)-fusion forms of these three proteins were able to co-precipitate p35nck5a complexed with Cdk5 from insect cell lysate. Among these three proteins, only C48 and C53 can be phosphorylated by Nclk, suggesting that they may be the substrates of Nclk. Sequence homology searches have suggested that the C48 protein is marginally related to restin protein, whereas the C42 protein has homologues of unknown function in Caenorhabditis elegans and Arabidopsis thaliana.
authors.affiliation: Department of Biochemistry, Hong Kong University of Science and Technology, Kowloon. bcyching@ust.hk
authors.forename: Y P
authors.initials: YP
authors.lastname: Ching
authors.forename: Z
authors.initials: Z
authors.lastname: Qi
authors.forename: J H
authors.initials: JH
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D018797:Cell Cycle Proteins; D002460:Cell Line; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D015870:Gene Expression; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism*; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D025521:Tumor Suppressor Proteins; D020798:Two-Hybrid System Techniques; D019885:Sulfur Group Transferases; D024101:Mitochondrial Proteins
chemical_list: D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D005982:Glutathione Transferase; D047908:Intracellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D025521:Tumor Suppressor Proteins; C405929:CDK5RAP2 protein, human; C405928:CDK5RAP3 protein, human; C089495:neuronal Cdk5 activator (p25-p35); C405930:CDK5RAP1 protein, human; D019885:Sulfur Group Transferases; D024101:Mitochondrial Proteins