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The Gabs in cell physiology
--
K Rathnakumar and Madhulika Dixit
Gab proteins comprise a growing family
of scaffolding/docking molecules involved in multiple signaling pathways mediated
by Receptor Tyrosine Kinases (RTKs) and non-RTK receptors. They have a Pleckstrin
Homology (PH) domain, a central Proline-Rich Domain (PRD) and multiple phosphorylation
sites which act as docking sites for other signaling proteins. These proteins
are necessary for normal development and angiogenesis. They play a role in homing
of haematopoeitic cells from bone marrow, glucose transport, cardiac hypertrophy,
oxidative stress and atherosclerosis. This paper reviews the structure and their
biological roles during normal growth, differentiation and development programs.
©
2008 IUP . All Rights Reserved.
Embryo Proteomics: An Emerging Technology
in Developmental Biology
-- Mukesh Kumar Gupta,
Sang Jun Uhmand Hoon Taek Lee
Knowing what, where and when different
proteins are expressed during embryonic development and how functional and structural
alterations of proteins control the development programs are fundamental issues
in developmental biology. Traditionally, this goal has been achieved using a
variety of elaborate molecular biological techniques including PCR-based approaches,
cDNA microarray and chip technologies to quantify mRNA transcripts of genes.
However, interpretation from these technologies is based on the assumption that
up- and down-regulation of mRNA accompanies functional changes in the cell,
which, in fact, does not hold in all instances. These questions have also been
addressed by studying one protein at a time, but a research tool that can handle
many proteins in parallel would be more valuable. Proteomics and proteomic techniques
can provide information about several proteins at a time and therefore are emerging
as valuable tools for embryological research. Mass spectrometry, applied as
key techniques in proteomic research, is providing new insights into the mechanism
of developmental biology and is expected to improve the efficiency of researchers
in exploring the unknown field. This review intends to provide some essential
information about mass spectrometry-based proteomics and their applications
to investigate embryo proteome.
©
2008 IUP . All Rights Reserved.
Stress Response and Emerging Roles
of Heat Shock Proteins: Bench to Bedside
-- Amere
Subbarao Sreedhar
The stress response is highly conserved
cellular response from prokaryotes to eukaryotes that is associated with the
synthesis of stress proteins or heat shock proteins (Hsps). Hsps form the most
ancient defense system in all living organisms on earth. These proteins function
as molecular chaperones helping in protein folding, assembly, translocation
and degradation. Available information on Hsps suggests that in addition to
their cytoprotective roles upon stress, Hsps are required for the normal cellular
functions such as development, differentiation, cell cycle, signal transduction
and many more. While the beneficial effects of Hsps under normal physiological
conditions and upon stress are gaining interest, cellular adaptations and civilization-associated
diseases, including cancers, are associated with high expression of Hsps contributing
to disease progression. Hsps are also involved in epigenetic regulation and
phenotypic evolution. Therefore considering the multitudes of involvement in
various cellular processes, Hsps are considered as molecular markers and pharmacological
targets for different disease and pathological models. Here, we review Hsps
involvement in biology and medicine, and discuss future perspectives of Hsps
research.
©
2008 IUP . All Rights Reserved.
Estimating the Distribution of Forms
of Cytochrome Oxidase from the Kinetics of Cyanide Binding
--
Simon Brown
Cytochrome oxidase preparations are
heterogeneous, so ligand binding to the purified enzyme is multiphasic. The
usual strategy when analyzing cyanide binding kinetics is to fit a multiexponential
expression to the progress curve. However, a more satisfying approach is to
fit a stretched exponential function from which the distribution of the rate
constants can be estimated. By analyzing the data in which a preparation of
the `fast' cyanide binding cytochrome oxidase is converted to the `slow' form
of the enzyme, it is shown that the use of the multiexponential function, rather
than the stretched exponential, is barely justified at best. Moreover, the stretched
exponential approach shows that the relatively narrow, almost normal distribution
of small time constants (t) observed with the `fast' form of the enzyme
becomes a broad, long-tailed distribution in the `slow' form of the enzyme.
The enzyme heterogeneity inferred from the multiexponential model can be characterized
unambiguously using the stretched exponential model.
©
2008 IUP . All Rights Reserved.
Review on Pandanus amaryllifolius Roxb.: The Plant with
Rich Source of Principle Basmati Aroma Compound 2 Acetyl-1-Pyrroline
-- A
B Nadaf, K V Wakte, R J Thengane and N Jawali
Pandanus amaryllifolius, an herb, is
popularly used as a food additive to impart the pleasant basmati aroma. Interestingly,
the plant bears the same aroma principle 2 Acetyl-1-Pyrroline (2AP) that has
been reported in basmati and other scented rice varieties. Quantitatively, the
2AP content is the highest in this plant among the plant kingdom. The present
review highlights all the aspects of this plant. It originated in Moluccas islands
and subsequently spread across the tropical peninsular countries. The aroma
compounds are stored in papillae. Histochemically, the localization of 2AP in
these papillae has been detected. In the in vitro plantlets, developmental
pattern has been traced out. Besides 2AP, 3-methyl-2 (5H)-furanone 3-hexanol,
4-methylpentanol, 3-hexanone and 2-hexanone are the important volatile compounds
that are contributing in the aroma. Depending on the method of extraction, the
quantity of 2AP varies; however, solvent extraction method is found to give
the maximum amount of 2AP (14.10 ppm). The plant is also an important source
of several alkaloids, viz., pandamamarilactone-1,-31,-32, pandamarine, pandamarilactam-3Y,-3X,
pandamarilactonine-A and -B, pandanamine, norpandamarilactonine-A -B and pandamarilactonine-C
and -D. In addition, the protein pandanin exhibiting hemagglutanning activity
and antiviral activity against herpes simplex virus type-1 and influenza virus
has been isolated. Micropropagation protocol has been standardized. The genetic
relatedness among the populations across the West coast of India has been assessed
using ISSR markers, which showed that the genome is much conserved. The molecular
elucidation of higher levels of 2AP expression is being worked out. The report
demands awareness for the commercial plantation of the plant in India.
©
2008 IUP . All Rights Reserved.
Antibacterial Activity of Three Medicinal
Plants: Eucalyptus globulus, Aristolochial latas and Vitex negundo Against Enteric Pathogens
-- R Anand, C Sundaramorthi,
S Saritha and K Bhuvaneswari
Three medicinal plants—Eucalyptus
globulus, Aristolochia latasand Vitex negundo—were investigated
for their antibacterial activity against six enteric pathogens, namely P.
vulgaris, S. typhi, Citrobacter spp., E. coli, K. pneumoniae and E. aerogens,using disc diffusion and Minimum Inhibitory Concentration
(MIC) method. The medicinal plants tested revealed varying degrees of antibacterial
activity with maximum zone of inhibition 23 mm was obtained with ethanolic extracts
of E. globulusagainst E. aerogens(MIC 241 mg/mL) followed by
20 mm inhibition with ethanolic extracts of A. latas (MIC 280 mg/mL).
Out of the three solvents (ethanol, chloroform and acetone) used in this study,
ethanol was found to be very effective.
©
2008 IUP . All Rights Reserved.
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