Table 3.
Mutation | Location | Classification | Effect of Mutation |
---|---|---|---|
Q29X | N-terminal region | nonsense | NBCe1-A protein truncation |
R298S | N-terminal region | missense | - mistargeting: apical/basolateral membranes -abnormal interaction of the N- terminal region with the cytoplasmic region |
S427L | TM1 | missense | -mistargeting: predominant apical membrane -abnormal helix packing -decreased GHCO3 -impaired IHCO3 reversal at -Vm |
T485S | TM3 | missense | - altered ion interaction - electroneutral transport |
G486R | TM3 | missense | altered ion interaction |
R510H | TM4 | missense | ER retention |
W516X | TM4 | nonsense | truncation: all NBCe1 variants |
L522P | TM4 | missense | ER retension |
2311 delA | IL4 | frameshift | truncation: all NBCe1 variants |
A799V | TM10 | missense | - intracellular retention - decreased GHCO3 - bicarbonate-independent Gcation |
R881C | TM12 | missense | ER retention (ER) |
65 bp-del | C-terminal tail | frameshift | ER retention |
Numbered according to NBCe1-A amino acid sequence
GHCO3: bicarbonate conductance ; Gcation: cation conductance; IHCO3: bicarbonate-dependent current; -Vm: negative plasma membrane voltages