Characterization of multiple isoforms of protein 4.1R expressed during erythroid terminal differentiation.
AuthorsGascard P, Lee G, Coulombel L, Auffray I, Lum M, Parra M, Conboy JG, Mohandas N, Chasis JA
JournalBlood
PubMed ID9834247
'In erythrocytes, 80-kD protein 4.1R regulates critical membrane properties of deformability and mechanical strength. However, previously obtained data suggest that multiple isoforms of protein 4. 1, generated by alternative pre-mRNA splicing, are expressed during erythroid differentiation. Erythroid precursors use two splice acceptor sites at the 5'' end of exon 2, ... More
Connexin 43 hemichannels mediate the Ca2+ influx induced by extracellular alkalinization.
AuthorsSchalper KA, Sánchez HA, Lee SC, Altenberg GA, Nathanson MH, Sáez JC
JournalAm J Physiol Cell Physiol
PubMed ID20881238
'Although alkaline pH is known to trigger Ca(2+) influx in diverse cells, no pH-sensitive Ca(2+) channel has been identified. Here, we report that extracellular alkalinization induces opening of connexin 43 hemichannels (Cx43 HCs). Increasing extracellular pH from 7.4 to 8.5, in the presence of physiological Ca(2+)/Mg(2+) concentrations, rapidly increased the ... More
Polarized trafficking of the aquaporin-3 water channel is mediated by an NH2-terminal sorting signal.
AuthorsRai T, Sasaki S, Uchida S,
JournalAm J Physiol Cell Physiol
PubMed ID16135541
Epithelial renal collecting duct cells express multiple types of aquaporin (AQP) water channels in a polarized fashion. AQP2 is specifically targeted to the apical cell domain, whereas AQP3 and AQP4 are expressed on the basolateral membrane. It is crucial that these AQP variants are sorted to their proper polarized membrane ... More
Connexin43 and connexin26 form gap junctions, but not heteromeric channels in co-expressing cells.
AuthorsGemel J, Valiunas V, Brink PR, Beyer EC,
JournalJ Cell Sci
PubMed ID15128867
Many cells contain two (or more) gap junction proteins that are able to oligomerize with each other to form heteromeric gap junction channels and influence the properties of intercellular communication. Cx26 and Cx43 are found together in a number of cell types, but previous data have suggested that they might ... More
Genetic and biochemical analysis of high iron toxicity in yeast: iron toxicity is due to the accumulation of cytosolic iron and occurs under both aerobic and anaerobic conditions.
AuthorsLin H, Li L, Jia X, Ward DM, Kaplan J,
JournalJ Biol Chem
PubMed ID21115478
Iron storage in yeast requires the activity of the vacuolar iron transporter Ccc1. Yeast with an intact CCC1 are resistant to iron toxicity, but deletion of CCC1 renders yeast susceptible to iron toxicity. We used genetic and biochemical analysis to identify suppressors of high iron toxicity in ?ccc1 cells to ... More
In vivo requirement of the alpha-syntrophin PDZ domain for the sarcolemmal localization of nNOS and aquaporin-4.
AuthorsAdams ME, Mueller HA, Froehner SC
JournalJ Cell Biol
PubMed ID11571312
alpha-Syntrophin is a scaffolding adapter protein expressed primarily on the sarcolemma of skeletal muscle. The COOH-terminal half of alpha-syntrophin binds to dystrophin and related proteins, leaving the PSD-95, discs-large, ZO-1 (PDZ) domain free to recruit other proteins to the dystrophin complex. We investigated the function of the PDZ domain of ... More