BIN1 Localizes the L-Type Calcium Channel to Cardiac T-Tubules

Cardiac tubular-like membrane invaginations contain the membrane scaffolding protein BIN1, which tethers dynamic microtubules that deliver calcium channels directly to T-tubule membrane

Genome-wide Analyses Identify KIF5A as a Novel ALS Gene

To identify novel genes associated with ALS, we undertook two lines of investigation. We carried out a genome-wide association study comparing 20,806 ALS cases and 59,804 controls. Independently, we performed a rare variant burden analysis comparing 1,138 index familial ALS cases and 19,494 controls. Through both approaches, we identified kinesin family member 5A (KIF5A) as a novel gene associated with ALS. Interestingly, mutations predominantly in the N-terminal motor domain of KIF5A are causative for two neurodegenerative diseases: hereditary spastic paraplegia (SPG10) and Charcot-Marie-Tooth type 2 (CMT2). In contrast, ALS-associated mutations are primarily located at the C-terminal cargo-binding tail domain and patients harboring loss-of-function mutations displayed an extended survival relative to typical ALS cases. Taken together, these results broaden the phenotype spectrum resulting from mutations in KIF5A and strengthen the role of cytoskeletal defects in the pathogenesis of ALS.Peer reviewe

Alcoholism: A Multi-Systemic Cellular Insult to Organs

Alcohol abuse can affect more than the heart and the liver. Many observers often do not appreciate the complex and differing aspects of alcohol’s effects in pathophysiologies that have been reported in multiple organs. Chronic alcohol abuse is known to be associated with pathophysiological changes that often result in life-threatening clinical outcomes, e.g., breast and colon cancer, pancreatic disease, cirrhosis of the liver, diabetes, osteoporosis, arthritis, kidney disease, immune system dysfunction, hypertension, coronary artery disease, cardiomyopathy, and can be as far-reaching as to cause central nervous system disorders. In this review article, we will discuss the various organs impacted by alcohol abuse. The lack of clear guidelines on the amount and frequency of alcohol intake, complicated by personal demographics, make extrapolations to real-life practices at best difficult for public health policy-makers

A mutation in the human phospholamban gene, deleting arginine 14, results in lethal, hereditary cardiomyopathy

The sarcoplasmic reticulum Ca(2+)-cycling proteins are key regulators of cardiac contractility, and alterations in sarcoplasmic reticulum Ca(2+)-cycling properties have been shown to be causal of familial cardiomyopathies. Through genetic screening of dilated cardiomyopathy patients, we identified a previously uncharacterized deletion of arginine 14 (PLN-R14Del) in the coding region of the phospholamban (PLN) gene in a large family with hereditary heart failure. No homozygous individuals were identified. By middle age, heterozygous individuals developed left ventricular dilation, contractile dysfunction, and episodic ventricular arrhythmias, with overt heart failure in some cases. Transgenic mice overexpressing the mutant PLN-R14Del recapitulated human cardiomyopathy exhibiting similar histopathologic abnormalities and premature death. Coexpression of the normal and mutant-PLN in HEK-293 cells resulted in sarcoplasmic reticulum Ca(2+)-ATPase superinhibition. The dominant effect of the PLN-R14Del mutation could not be fully removed, even upon phosphorylation by protein kinase A. Thus, by chronic suppression of sarcoplasmic reticulum Ca(2+)-ATPase activity, the nonreversible superinhibitory function of mutant PLN-R14Del may lead to inherited dilated cardiomyopathy and premature death in both humans and mice