The nBmp2 protein was first identified in a DNA affinity chromatography/mass spectrometry screen designed to detect proteins that interact with a cartilage-specific enhancer element (called D/E) from the type XI collagen gene Col11a2. The transcription factor SOX9, a protein from the Sox (SRY-related HMG box) family, binds to and activates gene expression from this enhancer. nBmp2 has no transcriptional activity of its own on this enhancer, but when co-transfected with SOX9 it increases SOX9's activation of D/E nearly 2-fold. SOX9 also activates cartilage-specific enhancer elements from the Col2a1, Col27a1, and Col9a1 genes. The purpose of this project was to determine 1) whether nBmp2 similarly effects SOX9-dependent expression from these enhancers, and 2) whether it does so by binding (either directly or indirectly) to the Col2a1, Col27a1, and Col9a1 enhancers. The work described in this thesis has shown that nBmp2 increases luciferase levels produced from three enhancer/reporter plasmids, but it does so without binding directly to the enhancers. This work has opened up a new area of exploration into the function of the novel protein nBmp2 to examine its potential effects on a variety of different gene regulatory processes.

According to the centers for disease control and prevention (CDC) and the world healthorganization (WHO), heart disease and immune related diseases such as diabetes and cancer areamong the leading causes of death around the world. Thus, the regulation of the function ofimmune cell plays a key role in health and disease. Calcium (Ca2+) ions play a critical role inimmune cell activation, function and in a robust immune response. Defects in Ca2+ signalinginfluences the development of cardiac disease, Alzheimer disease, immune cell metabolism,muscle dysfunction, and cancer. Each immune cell is unique in its activation and function,making it relevant to understand how activation of each type of immune cell is regulated. Herewe describe the role of the nBMP2 protein in macrophage activation and function and the role ofthe CD5 co-receptor in helper T cell activation and function.The nuclear bone morphogenetic protein 2 (nBMP2) is the nuclear variant of the bonemorphogenetic protein 2 (BMP2), a growth factor important in heart development, neurogenesis,bone, cartilage and muscle development. To better understand the function of nBMP2, transgenicnBMP2 mutant mice were generated. These mice have a slow muscle relaxation and cognitivedeficit caused in part by abnormal Ca2+ mobilization. Mutant nBMP2 mice also have an impairedsecondary immune response to systemic bacterial challenge. Here we have further characterizedmacrophage activation and function from mutant nBMP2 mice before and after bacterialinfection. We describe how nBMP2 influences the Ca2+ mobilization response and phagocytosisin macrophages, revealing a novel role of the nBMP2 protein in immune cell regulation.CD5 is a surface marker on T cells, thymocytes, and the B1 subset of B cells. CD5 isknown to play an important role during thymic development of T cells. CD5 functions as anegative regulator of T cell receptor (TCR) signaling and fine tunes the TCR signaling response.Here we describe our characterization of CD5 regulation of Ca2+ signaling in naïve helper Tcells. We also outline our findings examining how CD5-induced changes in helper T cellactivation influence other biological processes such as immune cell metabolism, the diversity ofthe gut microbiome, and cognitive function and behavior. Thus, this work elucidates theinfluence of the CD5 co-receptor on the functional outcomes in multiple systems when CD5 isaltered.