Figure 1 | Scientific Reports

Figure 1

From: HnRNP L and hnRNP LL antagonistically modulate PTB-mediated splicing suppression of CHRNA1 pre-mRNA

Figure 1

Ultrastructure of the patient endplate, identified mutations and their functional consequences.

(a) AChR expression at the patient and control endplate visualized with peroxidase-labeled α-bungarotoxin. Note restricted distribution and attenuated expression of AChR at the patient endplate. Bars = 1 μm. (b) Structure of CHRNA1 gene and two identified mutations. (c) Four possible transcripts in muscle of the patient. Only transcript I can make a normal α subunit. A segment spanning exon P3A of transcripts from αG421- and αR421-alleles is specifically amplified by allele-specific RT-PCR using patient muscle. Transcript I is not detectable (lanes 1 and 2). P3A(−) and P3A(+) transcripts are specifically amplified by allele-specific RT-PCR of patient muscle. Nested RT-PCR products spanning αG421R are digested by NlaIV, which cuts only the wild-type αG421 fragment (lane 4) and leaves the mutant αR421 fragment undigested (lanes 3 and 4). The P3A(−) transcript almost exclusively arises from an allele with αR421 (transcript III) (lane 3), whereas P3A(+) transcripts arise from both alleles (transcripts II and IV) (lane 4). Again, transcript I is not detectable (lanes 3 and 4). (d) Allele-specific real-time RT-PCR of patient muscle. The αP3A23′G > A allele barely generates P3A(−) transcript. (e) Expression of AChR on the HEK293 cell surface introduced with the indicated α cDNAs along with the wild-type β, δ and ε cDNAs. The expression level of αG421R-AChR is 14.7 ± 5.1% of normal (mean ± SD, n = 3).

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