As an important part of the cytoskeleton, microtubules play a crucial role in many cellular processes, such as cell division, intracellular transport, and maintaining cell morphology. The MAP1 family is an important family of microtubule-associated proteins, which includes three members: MAP1A, MAP1B, and MAP1S. These proteins are widely involved in the dynamic regulation of the cytoskeleton and play a key role in the development and function of the central nervous system, especially in the development and function of neurons. This study reviews the research progress of the MAP1 family, mainly focusing on the structure and function of MAP1 family members, and paying particular attention to their roles in neuronal development and regeneration, regulatory mechanisms, and neurodegenerative diseases.
Humans ; Animals ; Microtubule-Associated Proteins/classification* ; Neurons/cytology* ; Neurodegenerative Diseases/physiopathology* ; Microtubules/physiology* ; Cytoskeleton/physiology*

The research on intracellular trafficking of adenovirus has been described mainly through observations of subgroup C adenoviruses in transformed cell lines. The basic elements of the trafficking pathway include binding to receptors at the cell surface, internalization by endocytosis, lysis of the endosomal membrane, escape to the cytosol, intracellular trafficking along microtubules, nuclear pore docking, and viral genome translocation into the nucleus. More than 80% of the adenovirus genome is delivered to the nucleus in a highly efficient manner in approximately 1 h. However, exceptions to this trafficking pattern have been noted, including: variations based on target cell type, cell physiology, and adenovirus serotype. This review summarizes mechanism of adenovirus infection pathway and intracellular trafficking, providinging a foundation for the development of clinical adenoviral vector.
Adenoviridae ; physiology ; Cell Membrane ; virology ; Cell Nucleus ; virology ; Cytoplasm ; virology ; Endocytosis ; Endosomes ; virology ; Genetic Vectors ; Humans ; Microtubules ; Virus Internalization

The dynamic behaviour of a microbubble confined within a rigid micro-tube was studied using finite element method. The results indicated that the microbubble oscillation was limited when constrained within the micro-tube. Both the expansion ratio of its effective radius and natural frequency decreased with the decrease of the tube radius. Meanwhile, the deformation of the microbubble was non-spherical and became more significant when the ultrasound pressure amplitude increased. The dynamic behaviour in micro-tube was different from that in infinite liquid.
Blood Vessels ; physiology ; Contrast Media ; Finite Element Analysis ; Microbubbles ; Microtubules ; Molecular Dynamics Simulation

This study was conducted to evaluate the microtubule distribution following control of nuclear remodeling by treatment of bovine somatic cell nuclear transfer (SCNT) embryos with caffeine or roscovitine. Bovine somatic cells were fused to enucleated oocytes treated with either 5 mM caffeine or 150 micrometer roscovitine to control the type of nuclear remodeling. The proportion of embryos that underwent premature chromosome condensation (PCC) was increased by caffeine treatment but was reduced by roscovitine treatment (p < 0.05). The microtubule organization was examined by immunostaining beta- and gamma-tubulins at 15 min, 3 h, and 20 h of fusion using laser scanning confocal microscopy. The gamma-tubulin foci inherited from the donor centrosome were observed in most of the SCNT embryos at 15 min of fusion (91.3%) and most of them did not disappear until 3 h after fusion, regardless of treatment (82.9-87.2%). A significantly high proportion of embryos showing an abnormal chromosome or microtubule distribution was observed in the roscovitine-treated group (40.0%, p < 0.05) compared to the caffeine-treated group (22.1%). In conclusion, PCC is a favorable condition for the normal organization of microtubules, and inhibition of PCC can cause abnormal mitotic division of bovine SCNT embryos by causing microtubule dysfunction.
Animals ; Caffeine/pharmacology ; Cattle/embryology/*physiology ; Cell Nucleus/drug effects/*physiology/ultrastructure ; Female ; Fertilization in Vitro/veterinary ; Male ; Microscopy, Confocal/veterinary ; Microtubules/drug effects/*physiology/ultrastructure ; Nuclear Transfer Techniques/veterinary ; Oocytes/*physiology ; Pregnancy ; Purines/pharmacology

Liver cancer is one of the most common neoplastic diseases with high mortality in China. Currently, antimicrotubule drugs such as paclitaxel (PTX) and vincristine (VCR), are used as the common agents in the clinical chemotherapy for liver cancer. However, the responses of patients to these drugs vary markedly. Successful identification of intracellular factors influencing liver cancer's sensitivity to antimicrotubule drugs would be of great clinical importance. In this study, by engineering human hepatoma cell HepG2 to overexpress synuclein-gamma (SNCG), we investigated if SNCG is a molecular factor associated with the sensitivity to antimicrotubule drug treatment. Real-time RT-PCR and Western blotting assays showed SNCG was successfully overexpressed in HepG2/ SNCG cells compared with HepG2/Neo cells. The overexpressed SNCG altered the proliferation activity in HepG2 cells, which was 66% higher than that of HepG2/Neo cells through MTT method. The overexpressed SNCG also reduced sensitivity of HepG2 cells to antimicrotubule drugs: after PTX or VCR treatment, the proportion of HepG2/SNCG cells in G2/M arrest was significantly lower than that in HepG2/Neo cells. Correspondingly, HepG2/SNCG cells showed significantly lower mitotic index than HepG2/Neo cells. Meanwhile, HepG2/SNCG cells showed higher resistance to PTX and VCR than HepG2/Neo cells, with resistance index 21 and 15 respectively. Our studies suggested that the overexpression of SNCG could confer resistance to antimicrotubule drugs in hepatoma cells; and it indicated that SNCG may be as a potential response marker for antimicrotubule drugs in liver cancer chemotherapy.
Antineoplastic Agents, Phytogenic ; pharmacology ; Cell Cycle ; Cell Proliferation ; Drug Resistance, Neoplasm ; Gene Expression Regulation, Neoplastic ; Genetic Vectors ; Hep G2 Cells ; drug effects ; metabolism ; Humans ; Microtubules ; drug effects ; Mitosis ; drug effects ; Mitotic Index ; Paclitaxel ; pharmacology ; Plasmids ; RNA, Messenger ; metabolism ; Transfection ; Vincristine ; pharmacology ; gamma-Synuclein ; biosynthesis ; genetics ; physiology

In this study we detected dynamic changes and function of beta-tubulin, a subtype of microtubule, during the first cleavage period in mouse parthenogenetic and in vitro fertilized embryos. Firstly, we compared the developmental potential of in vitro fertilized, parthenogenetic, and in vivo fertilized embryos in culture. Then, the dynamic changes of beta-tubulin and nucleus in parthenogenetic and in vitro fertilized preimplantation embryos were detected by immunofluorescence and confocal microscopy to analyze the role of microtubules in meiotic division and embryonic development. The results indicated that the development rate of in vivo fertilized embryos was significantly higher than that of in vitro fertilized or parthenogenetic embryos (P<0.05). However, there was no significant difference in developmental potential between in vitro fertilized and parthenogenetic embryos. During in vitro fertilization, oocyte was activated when sperm entered it. Oocyte resumed the second meiotic division. Condensed maternal chromosomes aligning at the equator of the spindle were pulled to the spindle poles by kinetochore microtubules in anaphase. Furthermore, in telophase, there were microtubules between the two sets of decondensed maternal chromosomes. One set formed the second polar body (Pb(2)), which was extruded to the perivitelline space. The other set formed female pronucleus. Meanwhile, 5-8 h after fertilization, sperm chromatin condensed and decondensed to form male pronucleus. Microtubule composed mesosome and cytaster remodeling around male and female pronuclei to form long microtubules, which pull the pronuclei to get close. During 4-6 h parthenogenetic activation, SrCl(2) activated oocytes to resume meiosis. As a consequence, sister chromatids were pulled to spindle poles. Cytochalasin B, which was applied in the medium, inhibited the extrusion of Pb(2). Two haploid pronuclei in the cytoplasm were connected by microtubules. Compared with that in in vitro fertilization, oocyte is easier to be activated in parthenogenetic activation. Chemical activation is more efficient than sperm penetration in in vitro fertilization as indicated by earlier and better remodeling of the microtubules.
Animals ; Blastocyst ; Cell Cycle ; Chromatin ; Embryonic Development ; Female ; Fertilization in Vitro ; Male ; Meiosis ; Mice ; Microtubules ; physiology ; Oocytes ; Parthenogenesis ; Pregnancy ; Sperm-Ovum Interactions

AIMTo show whether molecular motor dynein on a microtubule track, molecular motor myosin Va, motor recruiter myosin Va, VIIa-Rab27a/b interacting protein (MyRIP), and vesicle receptor Rab27b on an F-actin track were present during human and monkey spermiogenesis involving intramanchette transport (IMT).

METHODSSpermiogenic cells were obtained from three men with obstructive azoospermia and normal adult cynomolgus monkey (Macaca fascicularis). Immunocytochemical detection and reverse transcription-polymerase chain reaction (RT-PCR) analysis of the proteins were carried out. Samples were analyzed by light microscope.

RESULTSUsing RT-PCR, we found that dynein, myosin Va, MyRIP and Rab27b were expressed in monkey testis. These proteins were localized to the manchette, as shown by immunofluorescence, particularly during human and monkey spermiogenesis.

CONCLUSIONWe speculate that during primate spermiogenesis, those proteins that compose microtubule-based and actin-based vesicle transport systems are actually present in the manchette and might possibly be involved in intramanchette transport.

Actins ; metabolism ; Adult ; Animals ; Biological Transport ; physiology ; Dyneins ; metabolism ; Humans ; Macaca fascicularis ; Male ; Microtubules ; metabolism ; Myosin Heavy Chains ; metabolism ; Myosin Type V ; metabolism ; Myosins ; metabolism ; Spermatids ; cytology ; metabolism ; Spermatogenesis ; physiology ; Testis ; cytology ; metabolism ; Transport Vesicles ; physiology ; Vesicular Transport Proteins ; metabolism ; rab GTP-Binding Proteins ; metabolism

Phosphoinositide-specific phospholipase C-gamma1 (PLC-gamma1) has two pleckstrin homology (PH) domains: an amino-terminal domain (PH1) and a split PH domain (PH2). Here, we show that overlay assay of bovine brain tubulin pool with glutathione-S-transferase (GST)-PLC-gamma1 PH domain fusion proteins, followed by matrix-assisted laser-desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), identified 68-kDa neurofilament light chain (NF-L) as a binding protein of amino-terminal PH domain of PLC-gamma1. NF-L is known as a component of neuronal intermediate filaments, which are responsible for supporting the structure of myelinated axons in neuron. PLC-gamma1 and NF-L colocalized in the neurite in PC12 cells upon nerve growth factor stimulation. In vitro binding assay and immunoprecipitation analysis also showed a specific interaction of both proteins in differentiated PC12 cells. The phosphatidylinositol 4, 5-bisphosphate [PI(4,5)P2] hydrolyzing activity of PLC-gamma1 was slightly decreased in the presence of purified NF-L in vitro, suggesting that NF-L inhibits PLC-gamma1. Our results suggest that PLC-gamma1-associated NF-L sequesters the phospholipid from the PH domain of PLC-gamma1.
Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Rats ; Protein Interaction Mapping ; Protein Biosynthesis/drug effects ; Protein Binding/drug effects ; Phosphoproteins/chemistry/*metabolism ; Phospholipase C gamma/antagonists & inhibitors/chemistry/*metabolism ; Phosphatidylinositol 4,5-Diphosphate/metabolism ; Peptides/chemistry/metabolism ; PC12 Cells ; Neurofilament Proteins/chemistry/*metabolism ; Nerve Growth Factor/pharmacology ; Molecular Weight ; Molecular Sequence Data ; Microtubules/metabolism ; Microscopy, Fluorescence ; Isoenzymes/metabolism/pharmacology/physiology ; Glutathione Transferase/metabolism ; Blotting, Far-Western ; Blood Proteins/chemistry/*metabolism ; Binding Sites ; Animals ; Amino Acid Sequence

OBJECTIVETo investigate the function of microtubules in volume overload cardiac hypertrophy of rat.

METHODSThe structure of microtubules was observed using an immunofluorescent microscope, while the pixel intensity and distribution of microtubule imaging was estimated from laser scanning confocal images of left ventricular cardiocytes immuno-labeled with an antibody to beta-tubulin.

RESULTSThe pixels of the microtubule image taken just after volume overload were not evenly distributed. At 6 hours after overload, the pixel intensity of the microtubule image was decreased to less than 150 (arbitrary units), which was the same as the pixel intensity and distribution of the colchicine depolymerized microtubule image. The changes were partially recovered to 200 (arbitrary units) after 4 more days. The pixel intensity of the control microtubule image was 250 (arbitrary units) and had an even distribution. The structuring of the microtubules was more disordered as volume overload hypertrophy developed.

CONCLUSIONSThere are disorders in the signal transduction pathways governing the hypertrophic response of cardiomyocytes in the hypertrophic myocardium and microtubule is one of the members of the signal transduction pathways governing the hypertrophic response of cardiomyocytes in the hypertrophic myocardium. The disordered microtubule array may be targeted during heart failure treatment.

Animals ; Cardiomegaly ; physiopathology ; Cyclic AMP ; analysis ; Disease Models, Animal ; Male ; Microtubules ; physiology ; Rats ; Rats, Sprague-Dawley ; Tubulin ; physiology

Plant cells response to water deficit through a variety of physiological processes. In this work, we studied the function of microtubule cytoskeleton during dehydration/rehydration cycle in moss (Atrichum undulatum) protonemal cells as a model system. The morphological and cytological change of protonemal cells during dehydration and rehydration cycle were first investigated. Under normal conditions, protonemal cells showed bright green colour and appeared wet and fresh. Numerous chloroplasts distributed regularly throughout the cytoplasm in each cell. After dehydration treatment, protonemal cells lost most of their chlorophylls and turned to look yellow and dry. In addition, dehydration caused plasmolysis in these cells. Upon rehydration, the cells could recover completely from the dehydrated state. These results indicated that moss had a remarkable intrinsic ability to survive from the extreme drought stress. Microtubule, an important component of cytoskeleton, is considered to play crucial roles in the responses to some environmental stresses such as cold and light. To see if it is also involved in the drought tolerance, dynamic organization of microtubules in protonemal cells of Atrichum undulatum subjected to drought and rehydration were examined by indirect immunofluorescence combined with confocal lasersharp scanning microscopy. The cortical microtubules were arranged into a fine structure with a predominant orientation parallel to the long axis of the cells in the control cells. After dehydration, the microtubule organization was remarkablly altered and the fine microtubule structure disappeared whereas some thicker cables formed. When the cells were grown under rehydration conditions, the fine microtubule arrays reappeared. These results provided a piece of evidence that microtubules play a role in the cellular responses to drought stress in moss. Furthermore, we analyzed the effects of the microtubule-disrupting agent colchicine on the morphology recovery of the protonemal cells during rehydration process. The cells were incubated with colchicine, followed by drought stress treatment and rehydration in the presence of colchicine to prevent recovery of microtubule organization. Results from immunofluorescence showed that microtubule arrays were broken down into smaller fragments. Compared to the cells treated with drought stress alone, the cells treated with drought stress in the presence of colchicine could not recover after rehydration treatment. The morphology resembled those of the drought treated cells, with obvious plasmolysis phenomena and loss of chlorophyll content. These results support the notion that microtubules were involved in the deccication tolerance mechanism in Atrichum undulatum.
Bryophyta ; metabolism ; physiology ; Droughts ; Gene Expression Regulation, Plant ; physiology ; Microscopy ; Microtubules ; metabolism