title: Cytosolic carboxypeptidase CCP6 is required for megakaryopoiesis by modulating Mad2 polyglutamylation.
abstract: Bone marrow progenitor cells develop into mature megakaryocytes (MKs) to produce platelets for hemostasis and other physiological functions. However, the molecular mechanisms underlying megakaryopoiesis are not completely defined. We show that cytosolic carboxypeptidase (CCP) 6 deficiency in mice causes enlarged spleens and increased platelet counts with underdeveloped MKs and dysfunctional platelets. The prominent phenotypes of CCP6 deficiency are different from those of CCP1-deficient mice. We found that CCP6 and tubulin tyrosine ligase-like family (TTLL) members TTLL4 and TTLL6 are highly expressed in MKs. We identify Mad2 (mitotic arrest deficient 2) as a novel substrate for CCP6 and not CCP1. Mad2 can be polyglutamylated by TTLL4 and TTLL6 to modulate the maturation of MKs. CCP6 deficiency causes hyperglutamylation of Mad2 to promote activation of Aurora B, leading to suppression of MK maturation. We reveal that Mad2 polyglutamylation plays a critical role in the regulation of megakaryopoiesis.
authors.affiliation: Key Laboratory of Infection and Immunity of CAS, Center for Laboratory Animal Research, Center for Biological Imaging, Key Laboratory of RNA Biology and Beijing Noncoding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Buqing
authors.initials: B
authors.lastname: Ye
authors.affiliation: Key Laboratory of Infection and Immunity of CAS, Center for Laboratory Animal Research, Center for Biological Imaging, Key Laboratory of RNA Biology and Beijing Noncoding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Chong
authors.initials: C
authors.lastname: Li
authors.affiliation: Key Laboratory of Infection and Immunity of CAS, Center for Laboratory Animal Research, Center for Biological Imaging, Key Laboratory of RNA Biology and Beijing Noncoding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Key Laboratory of Infection and Immunity of CAS, Center for Laboratory Animal Research, Center for Biological Imaging, Key Laboratory of RNA Biology and Beijing Noncoding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Yanying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Infection and Immunity of CAS, Center for Laboratory Animal Research, Center for Biological Imaging, Key Laboratory of RNA Biology and Beijing Noncoding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Hao
authors.affiliation: Key Laboratory of Infection and Immunity of CAS, Center for Laboratory Animal Research, Center for Biological Imaging, Key Laboratory of RNA Biology and Beijing Noncoding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory of Infection and Immunity of CAS, Center for Laboratory Animal Research, Center for Biological Imaging, Key Laboratory of RNA Biology and Beijing Noncoding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Du
authors.affiliation: Key Laboratory of Infection and Immunity of CAS, Center for Laboratory Animal Research, Center for Biological Imaging, Key Laboratory of RNA Biology and Beijing Noncoding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Hao
authors.affiliation: Key Laboratory of Infection and Immunity of CAS, Center for Laboratory Animal Research, Center for Biological Imaging, Key Laboratory of RNA Biology and Beijing Noncoding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Benyu
authors.initials: B
authors.lastname: Liu
authors.affiliation: Key Laboratory of Infection and Immunity of CAS, Center for Laboratory Animal Research, Center for Biological Imaging, Key Laboratory of RNA Biology and Beijing Noncoding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Wang
authors.affiliation: Key Laboratory of Infection and Immunity of CAS, Center for Laboratory Animal Research, Center for Biological Imaging, Key Laboratory of RNA Biology and Beijing Noncoding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Pengyan
authors.initials: P
authors.lastname: Xia
authors.affiliation: Key Laboratory of Infection and Immunity of CAS, Center for Laboratory Animal Research, Center for Biological Imaging, Key Laboratory of RNA Biology and Beijing Noncoding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Guanling
authors.initials: G
authors.lastname: Huang
authors.affiliation: Key Laboratory of Infection and Immunity of CAS, Center for Laboratory Animal Research, Center for Biological Imaging, Key Laboratory of RNA Biology and Beijing Noncoding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Sun
authors.affiliation: Key Laboratory of Infection and Immunity of CAS, Center for Laboratory Animal Research, Center for Biological Imaging, Key Laboratory of RNA Biology and Beijing Noncoding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China fanz@moon.ibp.ac.cn ytian@ibp.ac.cn.
authors.forename: Yong
authors.initials: Y
authors.lastname: Tian
authors.affiliation: Key Laboratory of Infection and Immunity of CAS, Center for Laboratory Animal Research, Center for Biological Imaging, Key Laboratory of RNA Biology and Beijing Noncoding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China fanz@moon.ibp.ac.cn ytian@ibp.ac.cn.
authors.forename: Zusen
authors.initials: Z
authors.lastname: Fan
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000166:cytology / Q000378:metabolism; D015153:Blotting, Western; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D002268:Carboxypeptidases / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics; D002478:Cells, Cultured; D003600:Cytosol / Q000201:enzymology; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D057809:HEK293 Cells; D006801:Humans; D020014:K562 Cells; D064246:Mad2 Proteins / Q000378:metabolism*; D008533:Megakaryocytes / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D046529:Microscopy, Electron, Transmission; D010453:Peptide Synthases / Q000235:genetics / Q000378:metabolism; D011099:Polyglutamic Acid / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D046929:Serine-Type D-Ala-D-Ala Carboxypeptidase / Q000235:genetics / Q000378:metabolism; D034061:Thrombopoiesis / Q000235:genetics / Q000502:physiology*
chemical_list: D064246:Mad2 Proteins; C577698:Mad2l1 protein, mouse; D011099:Polyglutamic Acid; C000596944:CCP6 protein, mouse; D002268:Carboxypeptidases; D046929:Serine-Type D-Ala-D-Ala Carboxypeptidase; C420042:Agtpbp1 protein, mouse; D019204:GTP-Binding Proteins; D010453:Peptide Synthases; C585750:TTLL6 protein, mouse