Novel Functions of SMN Complex Members and Their Implications in Spinal Muscular Atrophy

Bibliographic Details
Main Author: Walker, Michael Patrick
Language:English
Published: Case Western Reserve University School of Graduate Studies / OhioLINK 2009
Subjects:
SMN
SMA
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=case1238793216
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-case12387932162021-08-03T05:33:15Z Novel Functions of SMN Complex Members and Their Implications in Spinal Muscular Atrophy Walker, Michael Patrick Molecular Biology SMN Gemin4 SMN COMPLEX snRNP SMA calpain Z-disc Spinal Muscular Atrophy (SMA) is one of the most widespread genetic disorders in children. Genetic research into the disorder has identified the survival motor neurons 1 (SMN1) gene as the causative agent. The gene product, SMN, is found in a multiprotein particle, the SMN complex, required for the biogenesis of essential splicing factors, the U snRNPs. While much is known about the function of SMN within this complex, other member’s roles remain enigmatic. Recent investigations in muscle and motoneurons also point to additional functions for the SMN complex outside of snRNP biogenesis. These revelations have lead to a debate on whether or not SMA results from faulty snRNP production or from perturbation of another function(s). Clearly, a better understanding into all the members of the SMN complex would lead to a clearer view of snRNP biology and SMA etiology. The goal of my thesis was to determine the function of a little known member of the SMN complex, Gemin4, and investigate the role of the SMN complex in muscle function. Surprisingly, by utilizing a cell biological approach I discovered a putative role for Gemin4 with regard to import of the entire SMN complex. Gemin4 contains a functional nuclear localization signal (NLS) and can drive other members of the complex into the nucleus. The creation of a Gemin4 gene-trap mouse revealed that Gemin4 is essential. Finally, by using biochemical and genetic techniques, I discovered a novel role of the SMN complex in muscle function that is separate from snRNP biogenesis. At the molecular level the SMN complex is part of the contractile apparatus of both skeletal and cardiac muscle. Importantly, known muscle regulators, the calpains, directly process the core member of the complex, SMN. Mouse models of SMA show defective muscle phenotypes at the molecular level that are indicative of a novel role of the SMN complex. Thus, I have identified a novel function for a member of the SMN complex, Gemin4, and shown that the SMN complex has a separate function in striated muscle. My research adds substantial knowledge to the study of SMN complex function and SMA biology. 2009-07-21 English text Case Western Reserve University School of Graduate Studies / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=case1238793216 http://rave.ohiolink.edu/etdc/view?acc_num=case1238793216 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Molecular Biology
SMN
Gemin4
SMN COMPLEX
snRNP
SMA
calpain
Z-disc
spellingShingle Molecular Biology
SMN
Gemin4
SMN COMPLEX
snRNP
SMA
calpain
Z-disc
Walker, Michael Patrick
Novel Functions of SMN Complex Members and Their Implications in Spinal Muscular Atrophy
author Walker, Michael Patrick
author_facet Walker, Michael Patrick
author_sort Walker, Michael Patrick
title Novel Functions of SMN Complex Members and Their Implications in Spinal Muscular Atrophy
title_short Novel Functions of SMN Complex Members and Their Implications in Spinal Muscular Atrophy
title_full Novel Functions of SMN Complex Members and Their Implications in Spinal Muscular Atrophy
title_fullStr Novel Functions of SMN Complex Members and Their Implications in Spinal Muscular Atrophy
title_full_unstemmed Novel Functions of SMN Complex Members and Their Implications in Spinal Muscular Atrophy
title_sort novel functions of smn complex members and their implications in spinal muscular atrophy
publisher Case Western Reserve University School of Graduate Studies / OhioLINK
publishDate 2009
url http://rave.ohiolink.edu/etdc/view?acc_num=case1238793216
work_keys_str_mv AT walkermichaelpatrick novelfunctionsofsmncomplexmembersandtheirimplicationsinspinalmuscularatrophy
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