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Corticoid complex, a part of avian brain, has been suggested to play an important role in emotion, cognition and memory. It has been divided into intermediate corticoid area and dorsolateral corticoid area. The seasonal oscillations in the spaces between neurons have been taken into consideration, and it was observed that spaces between neurons, i.e. neuronal spacing in corticoid complex of female Indian ring-neck parrot (Psittacula krameri), significantly accredited during breeding time of bird. The result obtained in the present study as well as the previous studies highlighting other adjacent regions of brain (hippocampal complex) suggest better functioning and networking of the region concerned during active or breeding time of bird.

The posttranslational modification (PTM) in protein occurs in a regiospecific manner. In addition, the most commonly occurring PTMs involve similar residues in proteins such as acetylation, ubiquitylation, methylation and sumoylation at the lysine residue and phosphorylation and O-GlcNAc modification at serine/threonine residues. Thus, the possibility of modification sites where two such PTMs may occur in a mutually exclusive manner (ME-PTM) is much higher than known. A recent surge in the identification and the mapping of the commonly occurring PTMs in proteins has revealed that this is indeed the case. However, in what way such ME-PTM sites are regulated and what could be their relevance in the coordinated network of protein function remains to be known. To gain such potential insights in a biological context, we analyzed two most prevalent PTMs on the lysine residue by acetylation and ubiquitylation along with the most abundant PTM in proteins by phosphorylation among enzymes involved in glucose metabolism, a fundamental process in biology. The analysis of the PTM data sets has revealed two important clues that may be intrinsically associated with their regulation and function. First, the most commonly occurring PTMs by phosphorylation, acetylation and ubiquitylation are widespread and clustered in most of the enzymes involved in glucose metabolism; and the prevalence of phosphorylation sites correlates with the number of acetylation and ubiquitylation sites including the ME-modification sites. Second, the prevalence of ME-acetylation/ubiquitylation sites is exceptionally high among enzymes involved in glucose metabolism and have distinct pattern among the subset of enzymes of glucose metabolism such as glycolysis, tricarboxylic acid (TCA) cycle, glycogen synthesis, and the irreversible steps of gluconeogenesis. We hypothesize that phosphorylation including tyrosine phosphorylation plays an important role in the regulation of ME-acetylation/ubiquitylation sites and their similar pattern among the subset of functionally related proteins allows their coordinated regulation in the normal physiology. Similarly their coordinated dysregulation may underlie the disease processes such as reprogrammed metabolism in cancer, obesity, type 2 diabetes, and cardiovascular diseases. Our hypothesis provides an opportunity to understand the regulation of ME-PTMs in proteins and their relevance at the network level and is open for experimental validation.

The post-translational modification of protein by acetylation has been emerging as a prevalent modification in enzymes that catalyze intermediary metabolism. However, the dynamics of protein acetylation during adipocyte differentiation that involves a major shift in cellular metabolism is not known. In this study, we investigated the temporal changes in acetylation during adipocyte differentiation. Almost all acetylated proteins identified showed a sequential change in acetylation during the differentiation process. While the majority of the acetylated proteins showed a sequential upregulation during adipocyte differentiation, in a few proteins a sequential downregulation of protein acetylation was also observed. Our findings suggest that a wide-ranging temporal change in protein acetylation occurs during adipocyte differentiation including differentially expressed proteins signifying an important role in adipocyte differentiation.

An enzymatic posttranslational modification of proteins at serine or threonine residue by -N-acetyl glucosamine (GlcNAcylation, also known as O-GlcNAc modification), a product of hexosamine biosynthetic pathway (HBP), has been emerging as a fundamental regulatory mechanism like protein phosphorylation. A significant surge in the information in recent years due to technological advancement has implicated an important role for GlcNAcylation in a wide variety of cellular processes including cell division, metabolism, signal transduction and transcription. Furthermore, GlcNAcylation in proteins has been found to be intimately associated with phosphorylation which is one of the most diverse regulatory mechanisms in the biological system. Therefore, it is likely that altered protein GlcNAcylation may underlie etiology of various diseases including type 2 diabetes. Emerging evidence strongly indicates a role for GlcNAcylation in the development of insulin resistance, a hallmark of type 2 diabetes. Recent findings on protein GlcNAcylation, especially in relation to insulin signaling and insulin resistance have regenerated an immense interest in this field; which was first reported in early nineties. Here we summarize recent development in this area along with unanswered questions and future direction at the end. Some of the recently patented technologies in relation to GlcNAcylation are also summarized in this review. Further investigations in this area are timely and of critical importance with continuous increase in the incidence of type 2 diabetes and diabetes associated complications worldwide. A better understanding of the underlying mechanisms may provide new opportunities for the prevention and treatment of type 2 diabetes.

An enzymatic posttranslational modification of proteins at serine or threonine residue by β-N-acetyl glucosamine (GlcNAcylation, also known as O-GlcNAc modification), a product of hexosamine biosynthetic pathway (HBP), has been emerging as a fundamental regulatory mechanism like protein phosphorylation. A significant surge in the information in recent years due to technological advancement has implicated an important role for GlcNAcylation in a wide variety of cellular processes including cell division, metabolism, signal transduction and transcription. Furthermore, GlcNAcylation in proteins has been found to be intimately associated with phosphorylation which is one of the most diverse regulatory mechanisms in the biological system. Therefore, it is likely that altered protein GlcNAcylation may underlie etiology of various diseases including type 2 diabetes. Emerging evidence strongly indicates a role for GlcNAcylation in the development of insulin resistance, a hallmark of type 2 diabetes. Recent findings on protein GlcNAcylation, especially in relation to insulin signaling and insulin resistance have regenerated an immense interest in this field; which was first reported in early nineties. Here we summarize recent development in this area along with unanswered questions and future direction at the end. Some of the recently patented technologies in relation to GlcNAcylation are also summarized in this review. Further investigations in this area are timely and of critical importance with continuous increase in the incidence of type 2 diabetes and diabetes associated complications worldwide. A better understanding of the underlying mechanisms may provide new opportunities for the prevention and treatment of type 2 diabetes.

The prohibitins, Phb1 and Phb2 are highly conserved proteins in eukaryotic cells that are present in multiple cellular compartments. Initial investigations focused on the role of Phb1 as an inhibitor of cell proliferation hence the original name prohibitin. However both proteins appear to have a diverse range of functions and recent evidence suggests that the prohibitins have very similar but as yet only partially understood functions. In addition to their role as chaperone proteins in the mitochondria, and their ability to target to lipid rafts, their is now compelling evidence that both prohibitins are localized in the nucleus and can modulate transcriptional activity by interacting with various transcription factors, including the steroid hormone receptors, either directly or indirectly. In addition Phb1 and Phb2 are present in the circulation and can be internalized when added to cultured cells suggesting that the circulating prohibitins may have some regulatory role. This review presents some of the recent developments in prohibitin research and focuses on the similarities in the structure and function of these interesting proteins.

To investigate insulin-like growth factor (IGF)-independent effects of IGF binding protein-3 (IGFBP-3), T47D cells were enriched for a population of cells that expressed binding sites for biotinylated-IGFBP-3 by panning on streptavidin-coated plate. Proliferation of cell enriched for IGFBP-3 binding sites was significantly inhibited by IGFBP-3, whereas IGFBP-3 had no significant effect on the non-enriched cell population. Enriched and non-enriched cells were equally responsive to IGF-I, TGF-β and EGF. Conditioned medium from enriched cells had less IGFBP-3 than that from non-enriched cells. Cross-linking of biotinylated IGFBP-3 to T47D cell membranes identified complexes with Mr of 32, 80 and 100 kDa. All of these complexes were more abundant in enriched cells compared with the non-enriched cell population. These data demonstrate that despite the anti-proliferative effects of IGFBP-3 it is possible to selectively enriched for cell populations with more abundant IGFBP-3 binding sites. These enriched cells are more responsive to IGFBP-3 and secrete less of this binding protein than non-enriched cells, supporting the concept that IGFBP-3 secretion by human breast cancer cells may function as an autocrine or paracrine modulator of cell proliferation. (Mol Cell Biochem 267:83–89, 2004)

IGF‐I and their binding proteins are important in bone health. Examination of BMD, osteoblast proliferation, and markers of bone resorption in transgenic mice that constitutively overexpress IGFBP‐3 indicates that overexpression of IGFBP‐3 increases osteoclast number and bone resorption, impairs osteoblast proliferation, and has a significant negative effect on bone formation.

IGF‐I and their binding proteins are important in bone health. Examination of BMD, osteoblast proliferation, and markers of bone resorption in transgenic mice that constitutively overexpress IGFBP‐3 indicates that overexpression of IGFBP‐3 increases osteoclast number and bone resorption, impairs osteoblast proliferation, and has a significant negative effect on bone formation.Introduction:Low serum insulin‐like growth factor I (IGF‐I) levels correlate with an increased risk of osteoporotic fractures. Serum IGF‐I is largely bound to IGF‐binding protein‐3 (IGFBP‐3), which can inhibit IGF‐I action and enhance delivery of IGF‐I to tissues. Its role in bone biology is unclear.Methods:Bone mineral density (BMD), osteoblast proliferation, and markers of bone resorption were examined in transgenic (Tg) mice that constitutively overexpressed human IGFBP‐3 cDNA driven by either the cytomegalovirus (CMV) or phosphoglycerate kinase (PGK) promoter.Results:Cultured calvarial osteoblasts from Tg mice expressed the transgene and grew more slowly than cells from wild‐type (Wt) mice, and the mitogenic response to IGF‐I was attenuated in osteoblasts from Tg mice. Total volumetric BMD and cortical BMD, measured in the femur using peripheral quantitative computed tomography (pQCT) were significantly reduced in both Tg mouse strains compared with Wt mice. PGKBP‐3 Tg mice showed the most marked reduction in bone density. Osteocalcin levels were similar in Wt and CMVBP‐3 Tg mice but were significantly reduced in PGKBP‐3 Tg mice. Urinary deoxypyridinoline and osteoclast perimeter, markers of bone resorption, were significantly increased in both Tg mouse strains compared with Wt mice. Using double labeling with tetracycline, we demonstrated that pericortical and endocortical mineral apposition rate was significantly reduced in PGKBP‐3 Tg mice compared with Wt mice.Conclusions:These data show that overexpression of IGFBP‐3 increases osteoclast number and bone resorption, impairs osteoblast proliferation, and has a significant negative effect on bone formation.

In type II superconductors where the London penetration depthλis larger than the coherence lengthξ, there is a possibility of flux penetration inside the sample for magnetic field greater thanThe flux penetrates in the form of vortices with core of sizeξ. However these vortices differ from those in superfluid He4in variation of currentj(r) circulating around them. For superconductorsj(r) ∼ 1/ronly up to a distanceλand then it falls exponentially whilev(r) ∼ 1/rfor all distances in superfluids. The reason is that in superconductors vortex carries a magnetic flux which is screened by conduction electrons. This coupling of order parameter field (the pairing wavefunction) with the gauge field has many interesting implications for superconductors and for non-Abelian gauge theories. Some examples are as follows:The energy of the vortices is reduced. The energy of vortex of lengthL(ind= 3 sample) is of orderLlnLfor a superfluid, is of orderLin a superconductor, and (in ad= 2 sample) the energy of a vortex point which diverges like lnR(whereRis the size of the sample) in a superfluid becomes finite in a superconductor.The superconducting-normal transition in three dimension is very weak first order, because the fluctuations of the gauge field, when summed over, add to Ginzburg Landau free energy a term proportional to |ψ|3, whereψis the order parameter.Because of the lnrbehaviour of interaction energy of vortices, a two-dimensional superfluid sample can exhibit a Kosterlitz-Thouless type transition whereas a strictlyd= 2 superconductors should not have any. However for dirty superconducting films whereλis large vortex binding-unbinding transition can be observed with quite a rich phase diagram.