BRG

BRG may refer to:

FN BRG-15

FN BRG-15 was a heavy machine gun designed by Fabrique Nationale de Herstal as a potential replacement for the Browning M2HB .50 caliber machine gun.

History

It was announced in October 1983, FN were seeking to develop a more powerful replacement for the .50" Browning, better able to penetrate light armoured vehicles (in effect, a Western equivalent to the Soviet 14.5mm KPV heavy machine gun. FN initially selected the 20mm Hispano case as a basis and necked it down to 15mm for the FN-BRG (15x115). The weapon and its ammunition had a protracted development and finally emerged as a 15.5mm because of fast barrel wear.

The 15.5x106 was FN's second effort to make a KPV competitor in the BRG-15, appropriately by necking out the KPV's case. It also utilized an unusual dual feed device (A la Hafdasa C-4), with link ammunition belts feeding from both the right and left. Spent shell casings were ejected out of the bottom of the gun, as in FN's later P90 personal defense weapon. The quick-change barrel assembly developed for the BRG-15 was redesigned for use in an updated version of the M2HB.

SMARCA4

Transcription activator BRG1 also known as ATP-dependent helicase SMARCA4 is a protein that in humans is encoded by the SMARCA4 gene.

Function

The protein encoded by this gene is a member of the SWI/SNF family of proteins and is similar to the brahma protein of Drosophila. Members of this family have helicase and ATPase activities and are thought to regulate transcription of certain genes by altering the chromatin structure around those genes. The encoded protein is part of the large ATP-dependent chromatin remodeling complex SWI/SNF, which is required for transcriptional activation of genes normally repressed by chromatin. In addition, this protein can bind BRCA1, as well as regulate the expression of the tumorigenic protein CD44.

BRG1 works to activate or repress transcription. Having functional BRG1 is important for development past the pre-implantation stage. Without having a functional BRG1, exhibited with knockout research, the embryo will not hatch out of the zona pellucida, which will inhibit implantation from occurring on the endometrium (uterine wall). BRG1 is also crucial to the development of sperm. During the first stages of meiosis in spermatogenesis there are high levels of BRG1. When BRG1 is genetically damaged, meiosis is stopped in prophase 1, hindering the development of sperm and would result in infertility. More knockout research has concluded BRG1’s aid in the development of smooth muscle. In a BRG1 knockout, smooth muscle in the gastrointestinal tract lacks contractility, and intestines are incomplete in some cases. Another defect occurring in knocking out BRG1 in smooth muscle development is heart complications such as an open ductus arteriosus after birth.