【正文】
sduction Network 細胞信號轉(zhuǎn)導網(wǎng)絡的結構基礎 Ⅰ . Signaling Complex and its character ? Proteins won’t separated each other in cells but aggregated Protein plexfunctioning in life 1. Signaling plex ensures the efficiency, precision, variety ? Priority: ① directly contact, efficency, precision ② amplification ③ collaboration, variety ④ plex, multiple 2. Signaling plex exists at membrane and cytoskeleton structure ? Protein plex – existed in membrane structure or cell skeleton partmentation。 ? Advantage ① 由于已經(jīng)有相對固定的分子作為集合目標存在,有利于信號轉(zhuǎn)導分子 很快找到結合伴侶, 因此復合體轉(zhuǎn)導效率要高于一個完全自由擴散的系統(tǒng); ②在形成信號轉(zhuǎn)導復合體時,轉(zhuǎn)導分子將以有序的方式依次進入復合體, 因此信號轉(zhuǎn)導的 準確性 會高于自由擴散系統(tǒng)。 Ⅱ . Domain is substantial basis of proteinprotein interaction ? protein interaction domain 1. protprot interaction – mediated by domains ? Character of protein interaction domain (PID) ① one molecule contains ≥ two PID ② same domain existed in various proteins, but sequence are not exactly same – binding specificity ③ PID doesn’t have enzyme activity, just binding Distribution and role of protein interaction domain Protein kinase Btk PH TH SH3 SH2 催化區(qū) Adaptor Grb2 SH3 SH2 SH3 TF stat DNA 結合區(qū) SH2 TA Cytoskeleton tensin // SH2 PTB PID recognized motif Src homology 2 SH2 TyrPi Src homology 3 SH3 Pro rich pleckstrin homology PH Phospholipid derivation Protein tyrosine binding PTB TyrPi WW WW Pro rich Domain and its recognized motif 2. Src homology 2 (SH2) domain ? Src homology 2 domain: SH2 domian ? Function: the recognized motif is phosphorylated tyrosine and neighboring amino acids ? Different protein contains different SH2 selectivity 3. SH3 Domain ? Src homology 2 domain: SH3 domian ? Function: the recognized motif is prolinerich (910 Pro) sequence 4. PH Domain recognizes the phospholipids ? PH domain in pleckstrin in platelet, so called pleckstrin homology ? PH binding with membrane PL derivative,make