MCL-1, a well-known pro-survival BCL-2 family member, is indispensable for the survival of various cellular lineages and is also among the most frequently amplified genes in a variety of human malignancies. Gene ablation studies previously revealed that Mcl-1 deficiency leads to embryonic lethality around E3.5 during peri-implantation stage. Strikingly, the study did not detect any increase in apoptotic cells of the blastocyst, indicating a function of MCL-1 beyond regulating apoptosis. Our previous studies revealed an unrecognized role of MCL-1 in promoting mitochondrial physiology, which is independent of its classical anti-apoptotic function and requires being imported into the mitochondrial matrix. In order to understand the role of MCL-1 in early embryonic development, we used CRISPR-Cas9 to target Mcl-1’s start codon on established embryonic stem cells (ESCs). This approach resulted in the establishment of ESCs in which MCL-1’s N-terminus was truncated. Biochemical evaluation revealed that Nterminal- deleted MCL-1 retains anti-apoptotic function. However, this truncated MCL-1 is restricted to the mitochondrial outer membrane and functionally these mutated ESCs showed a dramatic defect in differentiation into the three embryonic germ layers- ectoderm, mesoderm, and ectoderm. These data suggest that in addition to MCL-1’s required antagonism of cell death by the C-terminal region, MCL-1’s N-terminus is required for efficient cellular differentiation, potentially by facilitating MCL-1’s import into the mitochondrial matrix.
","abstract_html":"<p>MCL-1, a well-known pro-survival BCL-2 family member, is indispensable for the survival of various cellular lineages and is also among the most frequently amplified genes in a variety of human malignancies. Gene ablation studies previously revealed that Mcl-1 deficiency leads to embryonic lethality around E3.5 during peri-implantation stage. Strikingly, the study did not detect any increase in apoptotic cells of the blastocyst, indicating a function of MCL-1 beyond regulating apoptosis. Our previous studies revealed an unrecognized role of MCL-1 in promoting mitochondrial physiology, which is independent of its classical anti-apoptotic function and requires being imported into the mitochondrial matrix. In order to understand the role of MCL-1 in early embryonic development, we used CRISPR-Cas9 to target Mcl-1’s start codon on established embryonic stem cells (ESCs). This approach resulted in the establishment of ESCs in which MCL-1’s N-terminus was truncated. Biochemical evaluation revealed that Nterminal- deleted MCL-1 retains anti-apoptotic function. However, this truncated MCL-1 is restricted to the mitochondrial outer membrane and functionally these mutated ESCs showed a dramatic defect in differentiation into the three embryonic germ layers- ectoderm, mesoderm, and ectoderm. These data suggest that in addition to MCL-1’s required antagonism of cell death by the C-terminal region, MCL-1’s N-terminus is required for efficient cellular differentiation, potentially by facilitating MCL-1’s import into the mitochondrial matrix.</p>","abstract_has_math":false,"creators":["Yang, Xue"],"institution":null,"degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation","degree_discipline":"Biomedical Sciences","degree_department":null,"school":null,"contributors":["Joseph T. Opferman, Ph.D."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2017,"date_issued":"2017-12-01T08:00:00Z","date_published":"2017-12-01T08:00:00Z","updated_at":"2026-07-24T05:00:33Z","subjects":["Anti-apoptosis","BCL-2 family","CRISPR-Cas9","MCL-1","Non-canonical role","Stem cell differentiation","Genetic Phenomena","Medical Cell Biology","Medical Genetics","Medical Sciences","Medicine and Health Sciences","Neoplasms"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://dc.uthsc.edu/dissertations/451","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Joseph T. 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Gene ablation studies previously revealed that Mcl-1 deficiency leads to embryonic lethality around E3.5 during peri-implantation stage. Strikingly, the study did not detect any increase in apoptotic cells of the blastocyst, indicating a function of MCL-1 beyond regulating apoptosis. Our previous studies revealed an unrecognized role of MCL-1 in promoting mitochondrial physiology, which is independent of its classical anti-apoptotic function and requires being imported into the mitochondrial matrix. In order to understand the role of MCL-1 in early embryonic development, we used CRISPR-Cas9 to target Mcl-1’s start codon on established embryonic stem cells (ESCs). This approach resulted in the establishment of ESCs in which MCL-1’s N-terminus was truncated. Biochemical evaluation revealed that Nterminal- deleted MCL-1 retains anti-apoptotic function. However, this truncated MCL-1 is restricted to the mitochondrial outer membrane and functionally these mutated ESCs showed a dramatic defect in differentiation into the three embryonic germ layers- ectoderm, mesoderm, and ectoderm. These data suggest that in addition to MCL-1’s required antagonism of cell death by the C-terminal region, MCL-1’s N-terminus is required for efficient cellular differentiation, potentially by facilitating MCL-1’s import into the mitochondrial matrix.
"]},{"key":"dc:title","label":"Title","values":["Revealing a Non-canonical Role of Anti-apoptotic MCL-1 in Early Embryonic Development"]}]}],"canonical_facts":{"dc:contributor":["Joseph T. Opferman, Ph.D."],"dc:creator":["Yang, Xue"],"dc:date.available":["2018-11-12T08:00:00Z"],"dc:description.abstract":["MCL-1, a well-known pro-survival BCL-2 family member, is indispensable for the survival of various cellular lineages and is also among the most frequently amplified genes in a variety of human malignancies. Gene ablation studies previously revealed that Mcl-1 deficiency leads to embryonic lethality around E3.5 during peri-implantation stage. Strikingly, the study did not detect any increase in apoptotic cells of the blastocyst, indicating a function of MCL-1 beyond regulating apoptosis. Our previous studies revealed an unrecognized role of MCL-1 in promoting mitochondrial physiology, which is independent of its classical anti-apoptotic function and requires being imported into the mitochondrial matrix. In order to understand the role of MCL-1 in early embryonic development, we used CRISPR-Cas9 to target Mcl-1’s start codon on established embryonic stem cells (ESCs). This approach resulted in the establishment of ESCs in which MCL-1’s N-terminus was truncated. Biochemical evaluation revealed that Nterminal- deleted MCL-1 retains anti-apoptotic function. However, this truncated MCL-1 is restricted to the mitochondrial outer membrane and functionally these mutated ESCs showed a dramatic defect in differentiation into the three embryonic germ layers- ectoderm, mesoderm, and ectoderm. These data suggest that in addition to MCL-1’s required antagonism of cell death by the C-terminal region, MCL-1’s N-terminus is required for efficient cellular differentiation, potentially by facilitating MCL-1’s import into the mitochondrial matrix.
"],"dc:identifier":["https://dc.uthsc.edu/dissertations/451"],"dc:subject":["Anti-apoptosis","BCL-2 family","CRISPR-Cas9","MCL-1","Non-canonical role","Stem cell differentiation","Genetic Phenomena","Medical Cell Biology","Medical Genetics","Medical Sciences","Medicine and Health Sciences","Neoplasms"],"dc:title":["Revealing a Non-canonical Role of Anti-apoptotic MCL-1 in Early Embryonic Development"],"thesis:degree_discipline":["Biomedical Sciences"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-24T05:00:33Z"}