the phosphorylation level of the plasma membrane protein in ..
are major constituents of the fiber cell plasma membrane that function to control the unique life long tissue physiology. Considerable proportion of these complexes are implemented in cell-cell communication, which is critical for lens homeostasis and transparency. Connexins, a classical type of communication proteins forming molecular channels, which interconnect cytoplasm of neighboring cells, has been shown to be a centerpiece of Gap Junctional Complexes. Our data, obtained in collaboration with Kumar Lab at UIC demonstrated that these complexes also include multifunctional adapter protein ZO1. Commonly found in epithelial tight junctions ZO1 exhibits a complex translocation pattern during fiber differentiation.
Aquaporin0 (MIP) form regular shaped square arrays, commonly found during EM imaging of fiber plasma membrane.
Adherence Junctional complexes provide structural integrity of lens fibers and lens in general. Until recently these abundant complexes formed by dosens of membrane proteins were largely overlooked by the research community. These complexes anchor cytoplasmic content to certain membrane microdomains supporting complex 3D envelope of the fiber’s plasma membrane.
A disintegrin/metalloprotease ADAM12 form microscopic plaque-like accumulations in fiber plasma membranes adjacent to gap junction complexes. This protein has multiple functions in mammalian tissues, but according to our data, in undifferentiated myoblasts and lens fibers ADAM12 is uniquely processed into 52 kDa isoform, implemented in membrane fusion. This may indicate that ADAM12 has a role in the core syncytium formation, that we recently characterized in the lens (in collaboration with Bassnett Lab at WashU). Few candidate membrane proteins are likely to be implemented in developmental cell-cell fusion. CD9, INT1B, CD47/MFR, TRAIL, Syncytin, ABC…, were reported to play role in mammalian developmental cell fusion but these data is still cell-type specific and controversial.
Role of plasma membranes in stimulation of RNA …
When insulin binds to its receptor, two pathwaysbecome activated: mitogen-activated protein kinase (MAPK) andphosphoinositide 3-kinase (PI3K) pathway (,).Activation of MAPK results in transmission of mitogenic signals tothe nucleus. Activation of the PI3K pathway leads to protein kinaseB (PKB) activation and conversion to its active form (Akt/PKB).Further activation of the mammalian target of rapamycin (mTOR)pathway enhances protein and fatty acid synthesis and inhibitsapoptosis (). Proteinshomologous to insulin, insulin-like growth factors I and II (IGF-Iand -II), regulate cellular growth and differentiation. This isaccomplished by signal transduction pathways through theirrespective receptors, IGF-IR and -IIR, and also by interactionswith insulin-like growth factor-binding proteins (IGFBPs), IGFBP-1through 6 (,). IGF-I binding to IGF-IR results inincreased cellular proliferation and apoptosis inhibition. IGF-IIhas a similar effect but its function is mainly limited to thefetal period, and plays a major role in the development of majororgans. IR and IGF-IR belong to a molecular class of proteinscalled tyrosine kinase receptors. Intracellular pathways activatedthrough IGF-IR by IGF-I are similar to those pathways activated byinsulin binding its receptor ().In high concentrations, insulin activates its own receptor, IR, aswell as IGF-IR, stimulating cellular growth and proliferation. Asimilar cross-receptor activation phenomenon was reported with highIGF-I concentrations ()(). High post-prandial orexogenously-administrated insulin levels lead to the inhibition ofIGFBP-1 synthesis and, therefore, result in increased free IGF-Iconcentrations ().Additionally, the activation of IGF-IR and IR appears to beaffected by the function of another class of regulatory proteinscalled tyrosine phosphatases. Specifically, protein tyrosinephosphatase 1B (PTP1B) acts directly on IR, resulting in decreasedcellular insulin sensitivity. Furthermore, IR inhibitors appear toincrease insulin sensitivity, especially in tumor cells ().
AAC is a membrane protein that acts like a revolving door - transporting ADP into mitochondria (to be converted to ATP) and ATP out of mitochondria and into the cytoplasm (Wang and Tajkhorshid 2008).
Outline the role of ribosomes in protein synthesis
NKT cells are the subject of many studies evaluatingthe role of the immune system in autoimmune diseases and malignancy(–). They are aptly named ‘natural killerT cells’ due to the cells possessing surface T-cell markers(CD3-TCR complex), surface NK cell markers (CD56, 161 and 94), andmarker CD57. Studies suggest that NKT cells mature in the thymus,like B and T lymphocytes. A particularly large number of NKT cellsare located in the liver, accounting for up to 40% of total cellsin the organ. Conversely, NKT cells make up a very small percentageof peripheral blood lymphocytes, accounting for ~1–5% of allperipheral blood T cells ().Despite their low number, NKT cells play an important role inimmunoregulation. Due to their cytotoxic abilities, NKT cells arelikely involved in the elimination of certain pathogens, includingviruses, intracellular bacteria, and protozoa, as well as abnormalhost cells, such as tumor cells. The NKT cell receptor has lowmolecular variability and is able to recognize abnormal surfaceclass I MHC molecules presented by dysfunctional host cells, suchas host cells infected by viruses or intracellular bacteria ormalignantly-transformed host cells. NKT cells usually lack CD4 and8 surface markers and, when activated, secrete large concentrationsof IL-4 and IFN-γ (–). NKT cells, similar to T celllymphocytes, may also be subject to immune polarization, anobserved phenomenon when immune cells differentiate into distincteffector cell types in response to different cytokines.
What Is the Role of RNA in Protein Synthesis?
The most important molecular mechanisms underlyingthe development and progression of cancer in patients with DMinclude oxidative stresses, generation of reactive oxygen speciesand nitric oxide with subsequent damage to cell membranes and DNA,overproduction of lactate byproducts, and pathologicaloverexpression of certain enzymes. Additionally, derangements inthe insulin-receptor signal transduction pathways and an impairedimmune system may contribute to oncogenesis. Obesity and metabolicdisorders contribute to a chronic inflammatory state, dysfunctionalhumoral and cellular immune responses, and decreased number andactivity levels of NK and NKT cell populations. Additionally,studies have demonstrated an association between abnormal glucosemetabolism and increased incidence of multiple malignancies,including colorectal, pancreatic, liver, breast, endometrial andprostate cancers.