title: Mutations of Cx43 that affect B cell spreading in response to BCR signaling.
abstract: The gap junction (GJ) protein connexin 43 (Cx43) is both necessary and sufficient for B cell receptor (BCR)-mediated cell spreading. To address how Cx43 mediates this effect, we blocked its function genetically, by expressing mutants of Cx43, and pharmacologically, by using chemical inhibitors. While various point mutations of Cx43 inhibited B cell spreading, treatment with channel blocking drugs did not, suggesting that this response was independent of channel function. The critical region of Cx43 appears to be the cytoplasmic carboxyl-terminal (CT) domain, which has previously been shown to be important for B cell spreading. Consistent with this, mutations of either tyrosine 247 or 265 found in the CT were sufficient to inhibit spreading. Thus Cx43 may influence B cell spreading by mechanisms requiring protein binding to, or modification of, these sites in the CT tail.
authors: CELL and I-cubed (I) Research Groups, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada.
authors: Letitia
authors: L
authors: Falk
authors: May
authors: M
authors: Dang-Lawson
authors: José Luis
authors: JL
authors: Vega
authors: Farnaz
authors: F
authors: Pournia
authors: Kate
authors: K
authors: Choi
authors: Caren
authors: C
authors: Jang
authors: Christian C
authors: CC
authors: Naus
authors: Linda
authors: L
authors: Matsuuchi
keywords: B cell; B cell receptor; BCR; Connexin 43; Cx43; Gap junction protein; Hemichannel