Os09g02650

The rice Brittle Culm 12 (BC12) gene encodes a dual-targeting kinesin-4 protein, controls cell-cycle progression and wall properties in rice.

Function

This gene encodes a kinesin-4 protein, which is participated in cell-cycle progression, cellulose microfibril deposition and cell wall composition in the monocot plant rice. bc12 mutants display dwarfism resulting from a significant reduction in cell number and brittleness due to an alteration in cellulose microfibril orientation and wall composition. Similar to the typical kinesin-4 in animals,BC12 has an nuclear locational signal (NLS) and functions in mitosis.<ref name="ref1"Kwon M, Morales-Mulia S, Brust-Mascher I, Rogers GC, Sharp DJ, Scholey JM. The chromokinesin, KLP3A, drives mitotic spindle pole separation during prometaphase and anaphase and facilitates chromatid motility. Mol. Biol. Cell. 2004;15:219–233.</ref> BC12 is present in both the nucleus and cytoplasm and associated with microtubule arrays during cell division. BC12 interacts with CDKA;3 (cyclin-dependent kinase) and probably undergoing phosphorylation for the purpose of regulation. BC12 is essential to exert multiple roles in cell division and cell wall biogenesis in rice.

Mutation

bc12: A 26bp deletion in the 4th exon of one open reading frame (ORF), results in a frameshift. which is related with the dwarfism and brittleness phenotype.

Expression pattern

BC12 is universally expressed in all organs. with higher expression in panicles and culms. RNA in situ hybridization reveals that BC12 is expressed in young tissues, includeing the initiating adventitious roots, primary root tips, flower primordia and intercalary meristems, all tissues in which cells are undergoing vigorous cell division.

Structure

The CDS coordinates(5'-3') of this gene is from 1158082 to 1167873. The ORF of the BC12 is 3108 nucleotides long and encodes a kinesin protein of the kinesin-4 subfamily which is 1036 amino acid residues long. The predicted molecular weight is about 116386, and the predicted pI is 9.4858. BC12 harbors a conserved motor domain at the N-terminus, a neck linker after the motor domain,a long coiled-coil region and the NLS at the C-terminus. The coiled-coil region is responsible for dimerization. BC12 shows microtubule-dependent ATPase activity, and the neck linker plays a critical role for this activity.

Sequence

The sequence of this gene are as following:

  1 ATGACGATGG AGCACGGCGA GGATTGCTGC GTCAAGGTGG CCGTCCATGT  CCGCCCGCTC ATCGGCGACG AGAAGCTTCA GGGCTGTAAG GACTGCGTCT
 101 CCGTCGTCTC CGGCAAGCCG CAGGTTCAGA TCGGGAGCCA TTCCTTCACC  TTCGACCATG TGTACGGCAG CTCCGGCACG CCGTCGGCGG CCATGTTCGA
 201 GGAGTGCGTG GCGCCGCTCG TCGACGGCCT CTTCCAGGGC TACAACGCCA  CCGTGCTCGC ATACGGCCAG ACTGGGTCAG GGAAGACCTA CACCATGGGG
 301 ACGGCCTGCA AGGAGGGCTC ACACATTGGG ATTATCCCGC GTGCCATGGC  CACGCTGTTC GACAAGATCG ACAAGCTCAA GAACCAAGTA GAGTTCCAGC
 401 TGCGCGTTTC GTTTATTGAG ATTCTGAAAG AAGAGGTGAG GGATTTGCTT  GATCCTGCTA CTGCTGCTGT TGGCAAACTT GAGAATGGAA ATGGACATGC
 501 AACCAAGTTG TCGGTTCCAG GTAAACCCCC TGTTCAGATC CGGGAGGCGT  CGAACGGGGT CATAACGTTA GCAGGATCGA CCGAAGTGCA TGTCACTACC
 601 CAGAAAGAAA TGACGGCATG CCTTGAGCAA GGATCTCTGA GTCGTGCAAC  TGGAAGTACC AACATGAACA ACCAATCAAG TCGTTCCCAT GCCATCTTCA
 701 CAATCACATT GGAGCAGATG CGCAAAGCAG ATCCCATCAT GACTTTAGAT  GGAATGCCTA TTGAAGAGAT GAATGAAGAC TATCTCTGTG CCAAACTCCA
 801 CTTAGTAGAT CTTGCTGGAT CAGAACGTGC TAAAAGAACT GGTTCTGATG  GCCTTCGGTT TAAGGAAGGT GTTCATATCA ACAGAGGACT TCTTGCTCTT
 901 GGCAATGTCA TCAGTGCTCT CGGTGATGAG AAAAAGAGGA AAGAAGGCGC  TCATGTTCCT TACCGGGACA GCAAACTCAC TCGCCTTCTG CAGGACTCTC
1001 TAGGTGGAAA CAGCAAGACT GTAATGATAG CCTGTATTAG TCCAGCAGAT  ATCAATGCTG AAGAAACACT GAACACTTTG AAATATGCTA ACCGCGCTCG
1101 TAACATCCAG AATAAGCCAA TTGTAAATAG AAATCCTGTT GCTGATGAGA  TGAAAAGGAT GCGCCAGCAA ATTGAATACT TGCAAGCAGA ACTCGTTTCA
1201 GCTCGAGGAG GAGTTGTCTT AGATGATGTT CAGGGTCTCA GGGAAAGGAT  CTCAATGCTT GAACAGAAAA ATGAAGACCT TTGCAGGGAA CTGTATGACC
1301 TTCGCAACCA TGGTTACACT GATCCTTGTG AACCTGAACT GCAAAAAATT  GGAACTGGTT ACACTAAAGG TGAAGGGCTC AAAAGAAGCT TGCAAAGTAC
1401 AGAACCATTT GATGTCCCCA TGACTGACTC AGTAAGAGCA GGCAGCCCTA  AAGATATTGA TGATGAAGTG GCCAAAGAAT GGGAACACAC AATGCTGCAG
1501 GATAGCATGG GCAAAGAGTT GAATGAATTA AACAGACAAC TGGAGCAAAA  GGAGTCTGAG ATGAAAATGT ATGGATCTGA CACTGTTGCA CTTAAACAAC
1601 ACTTTGGAAA GAAACTTTTG GAGCTTGAAG AAGAGAAAAG AGCTGTACAG  CAAGAAAGGG ACAGATTGTT AGCTGAAGTT GAAAGTCTAA ATGCTGATGG
1701 ACAAACACAC AAGTTGCGAG ATGCCCAGCT GCAAAAATTA AAAACCCTTG  AAGCACAGAT TCTAGACCTC AAGAAAAAGC AGGAGAACCA AGTTCAACTT
1801 CTGAAGGAAA AGCAAAAGAG TGATGAAGCT GCTAAGAAGT TGCAGGAAGA  AATTCATTCT ATAAAGGCAC AGAAGGTTCA ACTACAACAT AAAATCAAAC
1901 AAGAAGCGGA ACAATTCCGG CAATGGAAGG CTACCCGTGA AAAGGAACTC  CTGCAGTTGA GGAAAGAGGG GCGGCGAAAT GAGTATGAAC GCCACAAACT
2001 TCAAGCACTT AATCAGCGGC AGAAGTTGGT TTTGCAGAGG AAGACTGAAG  AAGCTGCGAT GGCTACCAAA AGGCTGAAAG AGTTACTAGA GGCTCGGAAA
2101 TCATCAGGAC GTGACAACTC AGGCATGAAT GGTACTTCTC CTGGCTCTCA  TATGACTGAG AAATCATTGC AAAAATGGCT AGAGCAAGAT TTGGAAGTCA
2201 TGGTGCATGT TCATGAAGTT CGAAACGAAT ATGAAAAGCA AAGTCAATTG  CGTGCTGCAC TTGGTGAGGA GCTTGCCATT TTAAAACAAG AAGATGTCAT
2301 GTCTGGTGCA GCTAGTCCGC CCAGAGGGAA GAATGGAAAC TCTAGGGCAA  ATACTTTGTC ACCAAATGCA AGACAAGCTA GGATAGCATC ACTTGAAAGC
2401 ATGGTGACAA TATCTTCAAA TACTCTCGTT GCTATGGCTT CTCAACTCTC  AGAAGCTGAA GAAAGAGAGC GTGCATTCTC TGGGCGTGGT CGGTGGAATC
2501 AGTTGCGTTC AATGGCAGAG GCAAAGAGTT TACTGCAGTA TATATTTAAC  GTTGCTGCAG ATGCAAGATG CCAAGTAAGG GAGAAAGAGA TGGAGATCAA
2601 GGAAATGAAG GAGCAAATGA CAGAGCTTGT GACCATCCTT CGACACAGCG  AATCACGTAG AAGGGAAACG GAAAAGCAGC TTAAGCAAAG AGAGCAGGCA
2701 GCTGTAACTG CCACTACATC TCCAGGAAAC GGAAATGGTT CAGTGAAGCA  CTCTGCTGAT GACTCCAACA CACCATTGTC ACCAGTTGCG GTGCCTGCAC
2801 AGAAGCAGCT GAAGTACTCT GCTGGAATTG TAAATAGCCC CAGCAAAGGG  GTTCCTGCAT TCAACAAACA ACATCTTAAG ATGGTTCCTA TGGCACAGTT
2901 GCCTGTTGGC AAGAAGGTTT CAATAGCAGG GCAATCAGGA AAACTTTGGA  GATGGAAAAG AAGCCACCAC CAGTGGCTAC TGCAGTTCAA GTGGAAGTGG
3001 CAAAAGCCCT GGAAATTGTC CGAGATGATT CGACACAGTG ACGAAACGAT  GACAAGGACT CGACCCAGAC CCCAGCTTCT TCCTCATAGA CCTCAAAGAG
3101 TGATGTGA

Knowledge extension

FRA1(FRAGILE FIBER 1) is the homolog gene of BC12 in Arabidopsis. FRA1 which is found in the cytoplasm,was the first functionally identified kinesin-4 member in plants. The fra1 mutant exhibits reduced plant height and fragile fibers as a result of aberrant deposition of cellulose microfibrils in the cell wall.

Reference

1 Kwon M, Morales-Mulia S, Brust-Mascher I, Rogers GC, Sharp DJ, Scholey JM. The chromokinesin, KLP3A, drives mitotic spindle pole separation during prometaphase and anaphase and facilitates chromatid motility. Mol. Biol. Cell. 2004;15:219–233. 2 Mazumdar M, Sundareshan S, Misteli T. Human chromokinesin KIF4A functions in chromosome condensation and segregation. J. Cell Biol. 2004;166:613–620. 3 Zhong R, Burk DH, Morrison WH, 3rd, Ye ZH. A kinesin-like protein is essential for oriented deposition of cellulose microfibrils and cell wall strength. Plant Cell. 2002;14:3101–3117.