Identification of a novel beta-tubulin subfamily with one member (TUBB4Q) located near the telomere of chromosome region 4q35.
The human beta-tubulin supergene family consists of several isotypes with many associated pseudogenes. Here we report the identification of yet another beta-tubulin sequence designated TUBB4Q. This tubulin maps 80 kb proximal to the facioscapulohumeral muscular dystrophy (FSHD1) associated D4Z4 repeats on chromosome 4q35. The genomic structure contains four exons encoding a putative protein of 434 amino acids. The TUBB4Q nucleotide and protein sequence show 87% and 86% homology to beta2-tubulin, respectively. Although the genomic structure shows all functional aspects of a genuine gene, no transcript could be detected. TUBB4Q-related sequences were identified on multiple chromosomes. Since these sequences mutually exhibit a high nucleotide sequence homology, they presumably belong to a novel subfamily of beta-tubulin genes. Although the chromosome 4q35 tubulin-member probably represents a pseudogene, ectopic expression due to a postulated position effect variegation (PEV), makes TUBB4Q an ideal dominant-negative candidate gene for FSHD1.
van Geel
M
M
Department of Cancer Genetics, Roswell Park Cancer Institute, Buffalo, NY, USA.
van Deutekom
J C
JC
van Staalduinen
A
A
Lemmers
R J
RJ
Dickson
M C
MC
Hofker
M H
MH
Padberg
G W
GW
Hewitt
J E
JE
de Jong
P J
PJ
Frants
R R
RR
D000483:Alleles; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001483:Base Sequence; D002894:Chromosomes, Human, Pair 4 / Q000235:genetics*; D003001:Cloning, Molecular; D005091:Exons / Q000235:genetics; D008040:Genetic Linkage / Q000235:genetics; D006801:Humans; D007438:Introns / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D020391:Muscular Dystrophy, Facioscapulohumeral / Q000235:genetics; D020161:Physical Chromosome Mapping; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics; D017434:Protein Structure, Tertiary; D011544:Pseudogenes / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D016615:Telomere / Q000235:genetics*; D014404:Tubulin / Q000737:chemistry / Q000235:genetics*
D012333:RNA, Messenger; C409879:TUBB7P protein, human; D014404:Tubulin