Cloning And Molecular Characters Of Porcine Klf4, Klf5, Klf7 And Egr2

KLFs (kruppel-like factors) are highly conserved basic transcription elementbinding protein (BTEP). There are conserved zinc finger domains at their C-termini thatcan bind specifically to the GC-rich promoter sequences of target genes, thus activatingor repressing their expression, and then regulate the proliferation and differentiation ofkinds of cells as well as the development of tissues. And cancer is often caused by theunlimited proliferation of cells due to the abnormal expression of these KLF factors.EGR2 (The early growth response factor 2) is another type of zinc finger containingbasal transcription factor which plays essential role in the development of nervoussystem.In this study, we cloned mRNA sequence including the full length CDS of porcineKlf5, Klf7 and Egr2, and cloned Intron3 of Klf4, Intron2 of Klf5, Intronl of Egr2 as wellas the chromosomal mapping of Klf4, Klf5 and Egr2. We also studied the expressionpattems of Klf4, Klf5, Klf7 and Egr2 in several porcine tissues as well as the effect ofinsulin and clenbuterol on their expression in the 3T3-L1 preadipocyte.1. We cloned the full length CDS of porcine Klf5 which is 1374 bp. It encodes a 457aa protein product which shares 95.8% and 89.4% identities with human and mouse,respectively.2. We cloned the 1112 bp Klf7 mRNA including its 909 bp full length CDS, Itencodes a 302 aa protein product which shares 98.3% and 97% identities with humanand mouse, respectively.3. We cloned the 1500 bp Egr2 mRNA including its 1416 bp full length CDS, Itencodes a 471 aa protein product which shares 91.8% and 88.4% identities with humanand mouse, respectively.4. We cloned Intron3 of Klf4, Intron2 of Klf5, Intronl of Egr2 which is 916 bp,1027 bp and 1342 bp respectively with the primers designed according to their CDSsequences.5. Porcine Klf4, Klf5, Egr2 was chromosomally localized at 1q28-29, 11q13-14 and14q23-25 respectively. And their chromosomal sits are corresponding to human chromosomal sits where their human counterparts were mapped.6. We used the semi-quantitative RT-PCR procedure to study the expression patternsof Klf4, Klf5, Klf7 and Egr2 in porcine muscle, white adipose, liver, spleen, gut, kidney,stomach, brain and heart.7. In 3T3-L1 preadipocyte, insulin stimulates the expression of Klf4, while inhibitsthe expression of Klf5 and Egr2; clenbuterol stimulates the expression of Klf4 andKlf5, while inhibits the expression of Egr2; Klf7 does not express in 3T3-L1preadipocyte.