Engineering Research Center for Cleaner Production of Textile Dyeing and Printing, Ministry of Education, Wuhan Textile University, Wu Han, 430073, China.
Mol Biol Rep. 2013 Feb;40(2):1219-26. doi: 10.1007/s11033-012-2164-0. Epub 2012 Oct 25.
Titin immunoglobulin domain protein (TTID) is localized to the Z-line and binds to alpha-actinin, gamma-filamin. It plays an indispensable role in stabilization and anchorage of thin filaments. In this study, the full-length cDNA sequence was isolated by the reverse transcription-polymerase chain reaction (RT-PCR) and the rapid amplification of cDNA ends (RACE). The TTID sequence was deposited into the Genbank under the accession no. DQ157551. The deduced protein of 499 amino acids showed 93 % identity to the corresponding human and rat sequence. Semi-quantitative RT-PCR revealed porcine TTID gene was expressed highest level in skeletal muscle, at second-highest level in the heart, but only low expression in the fat was detected. Bioinformatics analysis shows the molecular weight of the TTID protein is 55.747 kD with a PI of 9.26. It contains the protein function site of two potential Ig-like domain profiles, six N-myristoylation sites, six potential Casein kinase II phosphorylation sites, eight protein kinase C phosphorylation sites, three N-glycosylation sites, a tyrosine kinase phosphorylation site and a cell attachment sequence site. No putative base substitution was detected in the coding region by comparing sequences of Large White, Landrace and Meishan pig breeds. A T978C single nucleotide polymorphism in the intron 6 of porcine TTID gene was detected by a HinfI PCR-restriction fragment length polymorphism. Study showed allele frequency differences among four purebreds. Association of the genotypes with meat quality traits showed that different genotypes of porcine TTID gene were significantly associated with meat pH (m.Biceps Femoris) (P < 0.05), meat color value (m.longissimus Dorsi) (P < 0.05) and Water Moisture (m.longissimus Dorsi) (P < 0.05).
肌联蛋白免疫球蛋白结构域蛋白（TTID）定位于 Z 线并与α-辅肌动蛋白、γ-细丝蛋白结合。它在稳定和锚定细肌丝方面起着不可或缺的作用。本研究通过反转录-聚合酶链反应（RT-PCR）和快速扩增 cDNA 末端（RACE）分离全长 cDNA 序列。TTID 序列已在 Genbank 中注册，登录号为 DQ157551。推导出的 499 个氨基酸的蛋白质与相应的人和大鼠序列具有 93%的同一性。半定量 RT-PCR 显示，猪 TTID 基因在骨骼肌中表达水平最高，在心脏中次之，但在脂肪中仅检测到低表达。生物信息学分析表明，TTID 蛋白的分子量为 55.747kD，PI 为 9.26。它包含两个潜在的 Ig 样结构域特征的蛋白质功能位点、六个 N-豆蔻酰化位点、六个潜在的酪蛋白激酶 II 磷酸化位点、八个蛋白激酶 C 磷酸化位点、三个 N-糖基化位点、一个酪氨酸激酶磷酸化位点和一个细胞附着序列位点。通过比较大白猪、长白猪和梅山猪品种的序列，在编码区未发现潜在的碱基替换。在猪 TTID 基因的内含子 6 中检测到 T978C 单核苷酸多态性，通过 HindIII PCR-限制性片段长度多态性检测。研究表明，四个纯种猪之间等位基因频率存在差异。TTID 基因型与肉质性状的关联研究表明，猪 TTID 基因的不同基因型与肌肉 pH（m.Biceps Femoris）（P<0.05）、肌肉颜色值（m.longissimus Dorsi）（P<0.05）和水分（m.longissimus Dorsi）（P<0.05）显著相关。
