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Type II Transmembrane Protein (type + ii_transmembrane_protein)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Familial British dementia (FBD): a cerebral amyloidosis with systemic amyloid deposition

NEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 2 2002
J. L. Holton
Introduction:, FBD is an autosomal dominant disease with neuropathological similarities to Alzheimer's disease (AD) as it is characterized by amyloid angiopathy, parenchymal amyloid plaque deposition and neurofibrillary degeneration. FBD is associated with a stop codon mutation in the BRI2 gene encoding a type II transmembrane protein, BriPP. Mutation results in an extended precursor protein, ABriPP, from which a C-terminal 34 amino acid peptide (ABri) is generated by furin-like proteolytic cleavage and deposited as amyloid and preamyloid in the central nervous system. Despite the morphological parallels with AD the sequences of the amyloidogenic peptides, ABri in FBD and A, in AD, are completely different. We examined systemic tissues in FBD for ABri deposition. Materials and methods:, Immunohistochemistry using an ABri-specific antibody, Ab338, counterstained with Thioflavin S and Ab338 immuno-electron microscopy identified ABri deposits and determined whether these were amyloid or preamyloid in nature. Results:, Amyloid bearing blood vessels stained positively for ABri in myocardium, uterus, bladder, spleen, pancreas, lung and skeletal muscle. ABri was also identified in either amyloid or preamyloid conformation in the parenchyma of myocardium, adrenal, pancreas and skeletal muscle. Conclusion:, This study demonstrates that FBD is the first described cerebral amyloidosis with neurofibrillary pathology and dementia to be accompanied by systemic amyloid deposition. [source]

What's new in bullous pemphigoid

THE JOURNAL OF DERMATOLOGY, Issue 3 2010
Hideyuki UJIIE
Abstract Bullous pemphigoid (BP) is the most common autoimmune blistering disease. BP patients have autoantibodies against type XVII collagen (COL17, also called BP180 or BPAG2), a type II transmembrane protein that spans the lamina lucida and projects into the lamina densa of the epidermal basement membrane. The non-collagenous 16A domain of COL17 is considered to contain pathogenic epitopes of BP. The transfer of immunoglobulin (Ig)G from BP patients fails to cause blisters on mouse skin probably due to differences between humans and mice in the amino acid sequence of NC16A pathogenic epitope of COL17. Passive transfer of rabbit IgG antibodies against the murine homolog of human COL17 NC16A triggers immune reactions to COL17 in mice, including complement activation, mast cell degranulation and neutrophilic infiltration, resulting in dermal,epidermal separation. Recent studies using COL17-humanized mice that express human COL17 but lack murine COL17 were the first to demonstrate the pathogenicity of anti-COL17 human BP IgG autoantibodies in vivo. These new findings provide a greater understanding of BP pathomechanisms and facilitate the development of novel specific and efficient therapeutic strategies for BP. [source]

Prostate-specific membrane antigen and its truncated form PSM,

THE PROSTATE, Issue 5 2009
Petra Ml, ochová
Abstract BACKGROUND Prostate specific membrane antigen (PSMA) is a type II transmembrane protein overexpressed in prostate cancer as well as in the neovasculature of several non-prostatic solid tumors. In addition to full-length PSMA, several splice variants exist in prostatic tissue. Notably, the N-terminally truncated PSMA variant, termed PSM,, is prevalent in healthy prostate, and the ratio of PSMA/PSM, mRNA has been shown to correlate with cancer progression. The widely accepted hypothesis is that the PSM, protein is a translation product arising from the alternatively spliced PSM, mRNA. METHODS Differential ultracentrifugation, cell surface biotinylation, Western blotting, and enzyme activity measurement were used to study the origin and localization of the PSMA/PSM, variants in prostatic (LNCaP; lymph-node carcinoma of the prostate) and non-prostatic (HEK293) cell lines. These experiments were further complemented by analysis of the N -glycosylation patterns of the PSMA/PSM, proteins and by site-directed mutagenesis. RESULTS We identified PSM, protein expression in both the LNCaP cell line and a non-cancerous HEK293 human cell line transfected with a plasmid encoding full-length PSMA. Differential centrifugation revealed that PSM, is localized predominantly to the cytosol of both these cell lines and is proteolytically active. Furthermore, the PSM, protein is N -glycosylated by a mixture of high-mannose and complex type oligosaccharides and therefore trafficked beyond the cis -Golgi compartment. CONCLUSIONS Our data suggest that the PSM, protein is likely not generated by alternative splicing of the PSMA gene but by different mechanism, probably via an endoproteolytic cleavage of the full-length PSMA. Prostate 69:471,479, 2009. © 2008 Wiley-Liss, Inc. [source]

Met160Val polymorphism in the TRMPSS2 gene and risk of prostate cancer in a population-based case-control study

THE PROSTATE, Issue 4 2004
Joanna M. Lubieniecka
Abstract BACKGROUND Serine proteases play an important role in prostate cancer (PCa) invasion through the degradation of extracellular matrix proteins and interaction with growth modulating factors. The transmembrane serine protease 2 (TMPRSS2) gene encodes a type II transmembrane protein which, due to its cell surface localization, could be a potentially useful predictive marker for PCa. METHODS We screened a population of 24 unrelated individuals for sequence variants in the TMPRSS2 gene, and found a Met160Val change in 33%. We then tested 559 cases and 523 controls from a population-based case-control study of middle-aged men from Washington State. RESULTS Men with the GG genotype and a first-degree family history of PCa had a significantly higher risk for PCa relative to men without a family history (OR,=,2.05; 95% CI,=,1.3,3.2). However, the interaction between genotype and family history of PCa was not significant (P,=,0.52). CONCLUSIONS Larger, more detailed studies are needed to fully investigate the role of serine proteases in PCa. © 2004 Wiley-Liss, Inc. [source]