KChannelDB: Extraction of mutation data from the literature 2005, KChannelDB.
This data was extracted from Medline abstracts and full texts (when available) in an automated manner.
The table below describes the selected point mutation and provides links to other documents. The sentence(s) where the point mutation S143T was found are listed after the table.
The mutated residues are also indicated in the family sequence alignments and hyperlinked to the corresponding mutation pages.
Point mutation S143T in IRK5_RAT
- Point mutations to produce functional homomeric channels , Kir3.1(F137S) (22 ) , Kir3.2(S146T) , and Kir3.4(S143T) (23 ) , were produced
- One day after harvest , each oocyte was injected with 50 nl of mRNA for the TrkB receptor , and either G protein inwardly rectifying potassium channel heteromultimers Kir3.1 and Kir3.2 , Kir3.1 and Kir3.4 , or homomers Kir3.1(F137S) , Kir3.2(S146T) , or Kir3.4(S143T) into the vegetal pole
- Mutations in the putative pore of these channels , Kir3.1(F137S) and Kir3.4(S143T) greatly increased expression and activity of the channel homomers
- Moreover , the point mutation of Kir3.2(S146T) served as a control , as this change was similar to Kir3.1(F137S) and Kir3.4(S143T)
- The homomeric Kir3.4(S143T) was also highly sensitive to BDNF treatment
- A , the effects of BDNF treatment were measured in oocytes injected with 0.004 ng of TrkB mRNA plus the following: 0.05 ng of Kir3.1 and 0.05 ng of Kir3.2 , 1.0 ng of wild type Kir3.2 alone , 1.0 ng of Kir3.1(F137S) , Kir3.2(S146T) , or Kir3.4(S143T)
- BDNF treatment suppressed Kir3.4(S143T) current by 85 ± 2% (n = 11)
- Significant inhibition of the basal response was observed in all three homomeric channels: PMA treatment suppressed Kir3.1(F137S) by 65 ± 13% (n = 9) , suppressed Kir3.2(S146T) by 78 ± 6% (n = 7) , and suppressed Kir3.4(S143T) by 91 ± 2% (n = 14)
- Control oocytes expressing Kir3.1(F137S) , Kir3.2(S146T) , or Kir3.4(S143T) homomeric channels were compared with matched oocytes preincubated in PMA (100 nM , 10-15 min)
- Identification of Potential Phosphorylation Sites-- Potential sites of tyrosine phosphorylation in the Kir3 sequence were first studied by making an amino-terminal truncation of Kir3.4(S143T) (Fig. 5 )
- Using a polymerase chain reaction-based amplification , we prepared a cDNA template for mRNA encoding a Kir3.4(S143T) lacking amino acid residues 1-57
- Oocytes expressing the truncated Kir3.4(S143T) produced strong potassium currents that were not significantly (p > 0.05) suppressed by BDNF treatment
- After BDNF treatment , the mean current was 90 ± 11% (n = 8) of control compared with untreated oocytes expressing truncated Kir3.4(S143T) (Fig. 6 A)
- The effect of mutation of Tyr in the amino terminus of Kir3.4(S143T) and Kir3.1(F137S)
- A , oocytes were injected with 0.004 ng of TrkB and the following: 0.05 ng of Kir3.4(S143T) , 0.05 ng of Kir3.4(S143T / Del 1-57) , 1 ng of Kir3.4(S143T / Y32F) , 1 ng of Kir3.4(S143T / Y53F) , or 1 ng of Kir3.4(S143T / Y32F / Y53F)
- In contrast to the Kir3.4(S143T) , BDNF did not significantly (p < 0.05) inhibit the conductance of Kir3.4(S143T / Y32F) (Fig. 6 A)
- The same loss of BDNF sensitivity was observed with channels having tyrosine 32 mutated to aspartic acid to produce Kir3.4(S143T / Y32D) (data not shown)
- Mutation of the other tyrosine in the amino terminus of Kir3.4(S143T / Y53F) also significantly (p < 0.05) reduced the sensitivity to BDNF ; BDNF treatment caused only a reduction to 74 ± 5% (n = 11) of the control , untreated currents
- As expected , the deletion of both amino-terminal tyrosines to produce Kir3.4(S143T / Y32F / Y53F) also significantly blocked (p < 0.05) the effect of BDNF treatment 112 ± 8% (n = 15) (Fig. 6 A)
- These results suggest that tyrosine residues in both of these sites in the amino terminus of Kir3.4 (S143T) are critical for sensitivity to BDNF and are likely sites of tyrosine phosphorylation on Kir3.4
F.Horn (kchanneldbcmbi.ru.nl), 17-Aug-2005