外显子 （expressed region），是真核生物基因的一部分，它在剪接后仍会被保存下来，并可在蛋白质生物合成过程中被表达为蛋白质。 外显子是最后出现在成熟RNA中的基因序列，又称表达序列。 既存在于最初的转录产物中，也存在于成熟的RNA分子中的核苷酸序列。 通过确定在多种生物中出现的片段来鉴定编码区域，而外显子的保守性可以作为这种鉴定的基础。 4. 开放阅读框 ORF （open reading frame）它是理论上的蛋白编码区，一般是先在DNA序列中寻找起始密码 …

11 小时之前 · The product size of LDLR gene exon 4 was 501bp (Fig. 1). By using Sanger DNA sequencing, different variants in LDLR gene exon 4 were identified in 8 of female patients with MetS (3.85%; 8/208). No variants were detected in the remaining 200 (96.15%; 200/208) patients. The 104 control subjects did not show any variants in exon 4 of the LDLR gene.

An exon – EXpressed regiON - is any part of a gene that will form a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing. The term exon refers to both the DNA sequence within a gene and to the corresponding sequence in RNA transcripts.

断裂基因/中断基因 是指在DNA序列中，一系列可被表达成RNA或蛋白质的DNA片段（也就是外显子exon）被一系列不能转录成RNA或翻译成蛋白质的DNA片段（也就是intron）给分割开来。

Mutations in coding exon 4 of KRAS were found to occur commonly and to predict for a more favorable clinical outcome in patients with colorectal cancer. Exon 4 KRAS mutations, all of which were identified at amino acid residues K117 and A146, were associated with lower levels of GTP-bound RAS in isogenic models.

2015年7月1日 · Our findings that a human podocyte cell line expresses exon 4-positive and -negative APOL1 transcripts suggest that these variants may play a differential role in podocyte pathology. In summary, we have identified exon 4 as a …

2010年7月15日 · Models harboring exon 4 KRAS mutations exhibited mitogen-activated protein/extracellular signal-regulated kinase kinase dependence and resistance to EGFR-targeted agents. Our findings suggest that RAS mutation is not a binary variable in tumors, and that the diversity in mutant alleles and variability in gene copy number may also contribute to ...

2024年2月14日 · KRAS, the most frequently mutated oncogene in human cancer, produces two isoforms, KRAS4a and KRAS4b, through alternative splicing. These isoforms differ in exon 4, which encodes the final 15 residues of the G-domain and hypervariable regions (HVRs), vital for trafficking and membrane localization.

Exon-4 mutations at codon 146 affect an evolutionarily conserved region which is predicted to interact with the guanine base of GDP. These lesions do not impair intrinsic KRAS GTPase activity [24,27], but increase the rate of guanine nucleotide …

2021年7月3日 · We aimed to assess the prognostic value of KRAS exons 3 and 4 mutations to determine the necessity for their testing. Methods: KRAS mutations in exon 2/3/4 were evaluated in 1816 stage I-IV patients with colorectal adenocarcinoma. Results: The mutation rates of KRAS and KRAS exons 2, 3, and