Journal of Genes and Cells

21-26

Authors: Adel Ghorani-Azam, Seyed Ahmad Mohajeri, Bamdad Riahi-Zanjani, Sona Sepahi, Samaneh Sepahi

Amylase is an enzyme with broad hydrolysis activities that catalyzes the hydrolysis of starch into glucose and other small molecules such as maltose. It is an enzyme of glycoside family with surface layer homology (SLH) domain. SLH, which is known as cell wall binding domain is essential for binding to peptidoglycan of cell membranes. Since designing and producing enzymes with strong catalytic activity is essential in future food industry, investigating the similarities of amylases of different species can be helpful in protein engineering of these enzymes. Homology alignment of bacterial and human amylase sequences shows that both sequences contain 511 amino acid that are highly conserved with several repeated sequences that seems to be necessary for catalysis activity and structural conformation of the protein. In this study, we aimed to characterize the most critical structural and catalytic domains of amylase using bioinformatics tools. In this study, it was shown that SLH and starch binding domain (SBD) are extremely conserved in both human and bacterial amylase. In addition, it was shown that similar domain with several repeated di- or tri-peptide sequences existed in almost all amylases indicating that these residues may have valuable functional, structural and evolutional information. The results of this study may provide new insights into biological aspects of proteins that have not yet been elucidated.

32-35

Authors: Seyed Javad Mowla , Ensieh Poursani, Majid Mehravar, James E. Trosko

Alternative splicing is an important mechanism that regulates gene expression and function in mammals, particularly in primates and human. Large-scale studies estimates a large number of human genes undergo alternative splicing. OCT4, a crucial stem cell marker, is one of the most important stemness markers that is not excluded in this regard. Up until now, it is known that OCT4 can produce several spliced variants in different cell types. In this study, we used RT-PCR and DNA sequencing approaches to verify OCT4 variant expression. Here, we reported a novel OCT4 spliced variant which is named as OCT4B3, for the first time. This variant is very similar to the OCT4B2 transcript, but a 207-bp fragment has been lost from Exon1b. Moreover, we investigated the expression pattern of OCT4B3 in several human cancer cell lines and found its expression in two cell lines of 1321N1 and 5637. Our experiments resulted in discovery of a novel OCT4 variant of OCT4B3 that is expressed in two human 5637 and 1321N1 cell lines.