Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.6.4.4 (kinesin)
 5,033 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Microtubule-based ATPases of the kinesin superfamily provide the motile force for many animated features of living cells. Kinesin motors differ in their direction of movement along microtubules. Kinesin and ncd, a kinesin-related motor involved in formation and maintenance of mitotic and meiotic spindles, move in opposite directions along microtubules, even though their motor domains are 40% identical in amino-acid sequence. Here we report the crystal structure of the MgADP complex of the Drosophila ncd motor domain determined to 2.5A by X-ray crystallography, and compare it to the kinesin structure. The ncd and kinesin motor domains are remarkably similar in structure, and the locations of conserved surface amino acids suggest these motors share a common microtubule-binding site. Moreover, structural and functional comparisons of ncd, kinesin, myosin and G proteins indicate that these NTPases may have a similar strategy of changing conformation between NTP and NDP states. We propose a general model for converting a common gamma-phosphate-sensing mechanism into opposite polarities of movement for kinesin and ncd.
 ...
PMID:Crystal structure of the motor domain of the kinesin-related motor ncd. 860 61

We have identified two genes, roX1 and roX2, whose expression in the adult fly is restricted to neurons of males. The two genes reside on the X chromosome, and each encodes an RNA with no apparent open reading frame. Both genes are physically linked to female-specific genes that encode proteins expressed in the ovary: opt1, a novel peptide transporter, and nod, a member of the kinesin family. The male-specific transcripts are positively regulated by the dosage compensation pathway in an all-or-none fashion. Our data suggest that the multimeric complex of dosage compensation proteins may operate in different ways on different sets of X-linked genes.
 ...
PMID:Genes expressed in neurons of adult male Drosophila. 903 37

Mutations in the X-linked gene DCX result in lissencephaly in males, and abnormal neuronal positioning in females, suggesting a role for this gene product during neuronal migration. In spite of several known protein interactions, the involvement of DCX in a signaling pathway is still elusive. Here we demonstrate that DCX is a substrate of JNK and interacts with both c-Jun N-terminal kinase (JNK) and JNK interacting protein (JIP). The localization of this signaling module in the developing brain suggests its functionality in migrating neurons. The localization of DCX at neurite tips is determined by its interaction with JIP and by the interaction of the latter with kinesin. DCX is phosphorylated by JNK in growth cones. DCX mutated in sites phosphorylated by JNK affected neurite outgrowth, and the velocity and relative pause time of migrating neurons. We hypothesize that during neuronal migration, there is a need to regulate molecular motors that are working in the cell in opposite directions: kinesin (a plus-end directed molecular motor) versus dynein (a minus-end directed molecular motor).
 ...
PMID:DCX, a new mediator of the JNK pathway. 1476 23

Heterozygous LIS1 mutations are the most common cause of human lissencephaly, a human neuronal migration defect, and DCX mutations are the most common cause of X-linked lissencephaly. Lissencephaly is characterized by a smooth cerebral surface, thick cortex and dilated lateral ventricles associated with mental retardation and seizures due to defective neuronal migration. Lissencephaly due to the heterozygous loss of the gene LIS1 is a good example of a haploinsufficiency disorder. LIS1 was deleted or mutated in a large proportion of patients with lissencephaly in a heterozygous fashion. A series of studies discovered that LIS1 is an essential regulator of cytoplasmic dynein. Notably, the role of LIS1 in regulating dynein activity is highly conserved among eukaryotes. In particular, we reported that LIS1 and NDEL1 are essential for dynein transport to the plus-end of microtubules by kinesin, which is essential to maintain the proper distribution of cytoplasmic dynein within the cell. In addition, we report that mNUDC (mammalian NUDC) interacts with kinesin-1 and is required for the anterograde transport of a cytoplasmic dynein complex by kinesin-1. A microtubule organization and motor proteins are further modulated by post-translational modifications, including phosphorylation and palmitoylation. These modifications share a common pathway with mitotic cell division. For example, Aurora-A is activated during neurite elongation, and phosphorylates NDEL1, which facilitates microtubule extension into neurite processes. Elucidations of molecular pathways involving neuronal migrations provide us a chance to design a novel strategy for neurological disorder due to defective neuronal migration. For example, inhibition of calpain protects LIS1 from proteolysis resulting in the augmentation of LIS1 levels, which leads to rescue of the phenotypes that are observed in Lis1+/- mice. Endeavoring to address the regulation of the microtubule network and motor proteins will help in understanding not only corticogenesis but neurodegenerative disorders.
 ...
PMID:A unique role of dynein and nud family proteins in corticogenesis. 2239 75