Sperm-egg plasma membrane interaction is one of the important steps of mammalian fertilization. Many sperm and egg surface proteins are reported to be involved in sperm-zona pellucida interaction. Sulfogalactosylglycerolipid(SGG) is the major sulfoglycolipid in the germ cells of mammalian and lower vertebrates, mainly in the sperm head. It is a differentiation marker in spermatogenesis restricted to the zygotene and early pachytene spermatocytes. Sulfolipidimmobilizing protein 1 (SLIP1) is the major sulfoglycolipid of mammalian germ cells and eggs, with the same localization as SGG in the sperm. SLIP1 binds specificity to SGG, both playing a vital role in sperm-egg interaction. This article is aimed at reviewing the localization of SGG and SLIP1 in the germ cell surface and their role and related mechanism in gamete formation.
Animals ; Carrier Proteins ; physiology ; Cell Membrane ; physiology ; Female ; Galactolipids ; physiology ; Humans ; Male ; Sperm-Ovum Interactions ; physiology

It has been shown that mitochondria not only control their own Ca(2+) concentration ([Ca(2+)]), but also exert an influence over Ca(2+) signaling of the entire cell, including the endoplasmic reticulum or the sarcoplasmic reticulum, the plasma membrane, and the nucleus. That is to say, mitochondria couple cellular metabolic state with Ca(2+) transport processes. This review focuses on the ways in which the mitochondrial Ca(2+) handling system provides integrity and modulation for the cell to cope with the complex actions throughout its life cycle, enumerates some indeterminate aspects about it, and finally, prospects directions of future research.
Biological Transport ; Calcium Signaling ; Cell Membrane ; physiology ; Endoplasmic Reticulum ; physiology ; Mitochondria ; physiology ; Sarcoplasmic Reticulum ; physiology

Cell-to-cell connections provide conduits for signal exchanges, and play important functional roles in physiological and pathological processes of multicellular organisms. Membrane nanotubes are common long-distance connections between cells, not only transfer molecule signals and mitochondria, but also cooperate with gap junction and other cell-to-cell communications to transfer signals. During the last decade, there are many studies about membrane nanotubes, which focus on the similarities and differences between membrane nanotubes and other cell-to-cell communications, as well as their biological functions. In the present review, we summarized the latest findings about the structural diversity, the similarities and differences in signal transmission with other types of cell-to-cell communications, and physiological and pathological roles of membrane nanotubes.
Cell Communication ; Cell Membrane ; physiology ; Gap Junctions ; physiology ; Humans ; Mitochondria ; physiology ; Nanotubes

Atomic force microscopy (AFM) is an emerging technique for a variety of uses involving the analysis of cells. AFM is widely applied to obtain information about both cellular structural and subcellular events. In particular, a variety of investigations into membrane proteins and microfilaments were performed with AFM. Here, we introduce applications of AFM to molecular imaging of membrane proteins, and various approaches for observation and identification of intracellular microfilaments at the molecular level. These approaches can contribute to many applications of AFM in cell imaging.
Cell Membrane/ultrastructure ; Membrane Proteins/*physiology ; Microfilaments/*physiology ; *Microscopy, Atomic Force ; Molecular Imaging/*methods

Nogo-B is a major family member of the reticulon protein family 4. It is widely expressed in the central nervous system and peripheral tissues, and is mainly located in endoplasmic reticulum and cell membrane. Previous studies have revealed that Nogo-B plays a key role in vascular injury, tissue repair and inflammation process. It also may be critical for apoptosis of tumor cells and central diseases. Further investigation of the molecular characteristics and biological function of Nogo-B might be of great help to understand its role in diverse diseases.
Animals ; Apoptosis ; Cell Membrane ; physiology ; Endoplasmic Reticulum ; physiology ; Humans ; Inflammation ; Myelin Proteins ; physiology ; Nogo Proteins

Human zona pellucida (hZP) plays a critical role in the recognition, binding of sperms and oocytes, induction of acrosomal exocytosis, and avoidance of polyspermy. Human ZP is composed of four glycoproteins designated as hZP1, hZP2, hZP3 and hZP4. This paper reviews the actions of native hZP or recombinant hZP on acrosomal exocytosis and sperm-ZP binding.
Acrosome ; physiology ; Egg Proteins ; physiology ; Humans ; Male ; Membrane Glycoproteins ; physiology ; Receptors, Cell Surface ; physiology ; Spermatozoa ; physiology ; Zona Pellucida Glycoproteins

As the basic physiological function of synapses, vesicle cycling involves in many aspects of process. Among them, vesicle recycling is the basis of synaptic vesicle cycling. Studies show that clathrin mediated endocytosis is a major pathway of vesicle recycling, in which Dynamin plays an important role. Dynamin is a GTPases with molecular weight of 100 kD, which acts as "scissors" in the endocytosis, separating the clathrin coated pits from membrane. It has been found that Dynamin is associated with epilepsy, Alzheimer's disease, centronuclear myopathy, and several other neurological diseases. In this paper, we discussed the structure, function and regulation of Dynamin, and reviewed recent advance in the studies on Dynamin related diseases.
Clathrin ; physiology ; Coated Pits, Cell-Membrane ; physiology ; Dynamins ; physiology ; Endocytosis ; Humans ; Synapses ; physiology ; Synaptic Transmission ; Synaptic Vesicles ; physiology

The running courses of twelve meridians are explained through the electrical properties of cell membrane, and the phenomenon related with meridians such as mechanism of acupuncture analgesia and acupuncture anesthesia, pause of the propagated sensation along channels, nature of propagated sensation and width of propagated sensation is expounded in this article. As a result, it is held that the meridian system, a circulatory conduction system of bio-electricity of human, is an independent system from the known nine large systems.
Acupuncture Points ; Cell Membrane ; physiology ; Collateral Circulation ; Humans ; Meridians

AIMIn the present study, a variety of high resolution microscopy techniques were used to visualize the organization and motion of lipids and proteins in the sperm's plasma membrane. We have addressed questions such as the presence of diffusion barriers, confinement of molecules to specific surface domains, polarized diffusion and the role of cholesterol in regulating lipid rafts and signal transduction during capacitation.

METHODSAtomic force microscopy identified a novel region (EqSS) within the equatorial segment of bovine, porcine and ovine spermatozoa that was enriched in constitutively phosphorylated proteins. The EqSS was assembled during epididymal maturation. Fluorescence imaging techniques were then used to follow molecular diffusion on the sperm head.

RESULTSSingle lipid molecules were freely exchangeable throughout the plasma membrane and showed no evidence for confinement within domains. Large lipid aggregates, however, did not cross over the boundary between the post-acrosome and equatorial segment suggesting the presence of a molecular filter between these two domains.

CONCLUSIONA small reduction in membrane cholesterol enlarges or increases lipid rafts concomitant with phosphorylation of intracellular proteins. Excessive removal of cholesterol, however, disorganizes rafts with a cessation of phosphorylation. These techniques are forcing a revision of long-held views on how lipids and proteins in sperm membranes are assembled into larger complexes that mediate recognition and fusion with the egg.

Cell Membrane ; physiology ; ultrastructure ; Humans ; Male ; Membrane Lipids ; physiology ; Microscopy, Atomic Force ; Sperm Capacitation ; physiology ; Sperm Maturation ; physiology ; Spermatozoa ; cytology ; physiology

Membrane microparticles are shed from the plasma membrane of most eukaryotic cells when these cells were undergone activation or apoptosis, and released into the extracellular environment. Their composition depends on the cellular origin and processes triggering their formation. Several lines of evidence suggest that membrane microparticles might be able to facilitate cell-cell cross-talk and play an important roles in the regulation of survival, proliferation, differentiation, adhesion and chemotaxis of hematopoietic cells. Here, the components, mechanism of formation and the regulatory roles of membrane microparticles in hematopoiesis were reviewed.
Caveolae ; metabolism ; physiology ; Cell Membrane ; metabolism ; physiology ; Hematopoiesis ; physiology ; Humans ; Models, Biological ; R-SNARE Proteins ; metabolism ; physiology