HLA class I expression on human platelets is highly variable and correlates with distinct allele group frequencies.

Background: Human leukocyte antigen (HLA) class I molecules are expressed on platelets and can represent a source of alloimmunization in recipients of platelet transfusions. HLA mismatch between donors and recipients may be associated with the induction of anti-HLA antibodies, which can culminate in refractoriness to platelet transfusions. In the present study we analyzed HLA allele group frequencies and HLA expression levels on human platelets from blood donors.

Identification and characterization of three novel mutations in the CASQ1 gene in four patients with tubular aggregate myopathy.

Here, we report the identification of three novel missense mutations in the calsequestrin-1 (CASQ1) gene in four patients with tubular aggregate myopathy. These CASQ1 mutations affect conserved amino acids in position 44 (p.(Asp44Asn)), 103 (p.

Organization of junctional sarcoplasmic reticulum proteins in skeletal muscle fibers.

The sarcoplasmic reticulum (SR) of striated muscles is specialized for releasing Ca(2+) following sarcolemma depolarization in order to activate muscle contraction. To this end, the SR forms a network of longitudinal tubules and cisternae that surrounds the myofibrils and, at the same time, participates to the assembly of the triadic junctional membrane complexes formed by the close apposition of one t-tubule, originated from the sarcolemma, and two SR terminal cisternae. Advancements in understanding the molecular basis of the SR structural organization have identified an interaction between sAnk1, a transmembrane protein located on the longitudinal SR (l-SR) tubules, and obscurin, a myofibrillar protein.