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)

Kinesin, a microtubule-based force-generating molecule, is thought to translocate organelles along microtubules. To examine the function of kinesin in neurons, we sought to suppress kinesin heavy chain (KHC) expression in cultured hippocampal neurons using antisense oligonucleotides and study the phenotype of these KHC "null" cells. Two different antisense oligonucleotides complementary to the KHC sequence reduced the protein levels of the heavy chain by greater than 95% within 24 h after application and produced identical phenotypes. After inhibition of KHC expression for 24 or 48 h, neurons extended an array of neurites often with one neurite longer than the others; however, the length of all these neurites was significantly reduced. Inhibition of KHC expression also altered the distribution of GAP-43 and synapsin I, two proteins thought to be transported in association with membranous organelles. These proteins, which are normally localized at the tips of growing neurites, were confined to the cell body in antisense-treated cells. Treatment of the cells with the corresponding sense oligonucleotides affected neither the distribution of GAP-43 and synapsin I, nor the length of neurites. A full recovery of neurite length occurred after removal of the antisense oligonucleotides from the medium. These data indicate that KHC plays a role in the anterograde translocation of vesicles containing GAP-43 and synapsin I. A deficiency in vesicle delivery may also explain the inhibition of neurite outgrowth. Despite the inhibition of KHC and the failure of GAP-43 and synapsin I to move out of the cell body, hippocampal neurons can extend processes and acquire as asymmetric morphology.
 ...
PMID:Suppression of kinesin expression in cultured hippocampal neurons using antisense oligonucleotides. 153 97

Growth cones are intimately involved in determining the direction and extent of neurite elongation during development. They are able to monitor their environment and respond to it by undergoing directed motility. We have isolated a fraction enriched in growth cone particles from embryonic chick brain. Assayed by immunoblots, this fraction is enriched in GAP-43, and contains the cytoskeletal proteins actin, myosin II, neurofilament protein, tubulin, kinesin, and dynamin. All of the major components of focal adhesions are also present: alpha-actinin, vinculin, talin, and integrin. In addition to integrin, we also identify the cell adhesion molecules A-CAM, L1, fibronectin, and laminin in these particles. This preparation of isolated growth cone particles may be a useful model system for studying growth cone adhesion and motility.
 ...
PMID:Identification of cytoskeletal, focal adhesion, and cell adhesion proteins in growth cone particles isolated from developing chick brain. 183 41

In the present study, we present evidence about the cellular functions of KIF2, a kinesin-like superfamily member having a unique structure in that its motor domain is localized at the center of the molecule (Noda Y., Y. Sato-Yoshitake, S. Kondo, M. Nangaku, and N. Hirokawa. 1995. J. Cell Biol. 129:157-167.). Using subcellular fractionation techniques, isopicnic sucrose density centrifugation of microsomal fractions from developing rat cerebral cortex, and immunoisolation with KIF2 antibodies, we have now identified a type of nonsynaptic vesicle that associates with KIF2. This type of organelle lacks synaptic vesicle markers (synapsin, synaptophysin), amyloid precursor protein, GAP-43, or N-cadherin. On the other hand, it contains betagc, which is a novel variant of the beta subunit of the IGF-1 receptor, which is highly enriched in growth cone membranes. Both betagc and KIF2 are upregulated by NGF in PC12 cells and highly concentrated in growth cones of developing neurons. We have also analyzed the consequences of KIF2 suppression by antisense oligonucleotide treatment on nerve cell morphogenesis and the distribution of synaptic and nonsynaptic vesicle markers. KIF2 suppression results in a dramatic accumulation of betagc within the cell body and in its complete disappearance from growth cones; no alterations in the distribution of synapsin, synaptophysin, GAP-43, or amyloid percursor protein are detected in KIF2-suppressed neurons. Instead, all of them remained highly enriched at nerve terminals. KIF2 suppression also produces a dramatic inhibition of neurite outgrowth; this phenomenon occurs after betagc has disappeared from growth cones. Taken collectively, our results suggest an important role for KIF2 in neurite extension, a phenomenon that may be related with the anterograde transport of a type of nonsynaptic vesicle that contains as one of its components a growth cone membrane receptor for IGF-1, a growth factor implicated in nerve cell development.
 ...
PMID:Suppression of KIF2 in PC12 cells alters the distribution of a growth cone nonsynaptic membrane receptor and inhibits neurite extension. 924 93

HIKE is a highly conserved sequence motif identified as a candidate pleckstrin-homology (PH) domain binding site in Gbeta proteins, protein kinases, ankyrin and kinesin. HIKE motifs occur also in gelsolin, neurogranin, neuromodulin and in the PH domain of Bruton tyrosin kinase (BTK). Phosphatidylinositol-binding sequences more distantly related to HIKE are present in gelsolin, in the G protein-coupled receptor kinase 4 and in Trop-2. HIKE regions have been demonstrated to bind both proteins and lipids, and to regulate the interaction of Gbeta, neuromodulin and the BTK PH domain with downstream effectors and the cell membrane. Remarkably, mutations of the HIKE regions are common in diverse human genetic diseases. Several HIKE mutations in protein kinases lead to constitutive activation and cellular transformation, e.g. in MEN-2B, acute myeloid and mast cell leukemias, hereditary papillary renal carcinomas and multiple myeloma. Kinase-inactivating HIKE mutations cause Hirschsprung's disease, piebaldism, insulin resistance and developmental dysplasias. HIKE mutations in the PH domain of BTK lead to X-linked agammaglobulinemia, and different forms of amyloidosis are caused by mutations of HIKE-bearing molecules, for example gelsolin, Ret and Trop-2. Thus, quite diverse genetic diseases might share common molecular mechanisms. These include altered interactions of the mutated molecules with downstream effectors or the cell membrane, and defects in intracellular transport.
 ...
PMID:Large and diverse numbers of human diseases with HIKE mutations. 1076 24

Axonal transport of herpes simplex virus (HSV-1) is essential for viral infection and spread in the peripheral nervous system of the host. Therefore, the virus probably utilizes existing active transport and targeting mechanisms in neurons for virus assembly and spread from neurons to skin. In the present study, we used transmission immunoelectron microscopy to investigate the nature and origin of vesicles involved in the anterograde axonal transport of HSV-1 tegument and envelope proteins and of vesicles surrounding partially and fully enveloped capsids in growth cones. This study aimed to elucidate the mechanism of virus assembly and exit from axons of human fetal dorsal root ganglia neurons. We demonstrated that viral tegument and envelope proteins can travel in axons independently of viral capsids and were transported to the axon terminus in two types of transport vesicles, tubulovesicular membrane structures and large dense-cored vesicles. These vesicles and membrane carriers were derived from the trans-Golgi network (TGN) and contained key proteins, such as Rab3A, SNAP-25, GAP-43, and kinesin-1, involved in the secretory and exocytic pathways in axons. These proteins were also observed on fully and partially enveloped capsids in growth cones and on extracellular virions. Our findings provide further evidence to the subassembly model of separate transport in axons of unenveloped capsids from envelope and tegument proteins with final virus assembly occurring at the axon terminus. We postulate that HSV-1 capsids invaginate tegument- and envelope-bearing TGN-derived vesicles and utilize the large secretory vesicle pathway of exocytosis for exit from axons.
 ...
PMID:Herpes simplex virus utilizes the large secretory vesicle pathway for anterograde transport of tegument and envelope proteins and for viral exocytosis from growth cones of human fetal axons. 1917 21