Many linkage analyses have reproducibly reported 8p21-22 as a linkage hot locus for schizophrenia. The gene coding for neuregulin-1 is regarded as a factor that contributes to the linkage peak, but other genes may also be involved. Dr. Gurling and colleagues have conducted an excellent association study and obtained evidence that the gene coding for pericentriolar material 1 (PCM1) is associated with schizophrenia.

The results from the genetic portions of this are consistent with our unpublished biological study. (The abstract of Kamiya et al. has been submitted to SFN meeting at Atlanta in October 2006.) In exploring protein interactors of disrupted-in-schizophrenia-1 (DISC1), a promising risk factor for schizophrenia and bipolar disorder, we already came across PCM1 as a potential protein interactor of DISC1. This interaction has been confirmed by yeast two-hybrid and biochemical methods. In immunofluorescent cell staining, a pool of DISC1 and PCM1 are co-stained at the centrosome. Therefore, this genetic study is really encouraging us to move beyond our preliminary...  Read more

Many linkage analyses have reproducibly reported 8p21-22 as a linkage hot locus for schizophrenia. The gene coding for neuregulin-1 is regarded as a factor that contributes to the linkage peak, but other genes may also be involved. Dr. Gurling and colleagues have conducted an excellent association study and obtained evidence that the gene coding for pericentriolar material 1 (PCM1) is associated with schizophrenia.

The results from the genetic portions of this are consistent with our unpublished biological study. (The abstract of Kamiya et al. has been submitted to SFN meeting at Atlanta in October 2006.) In exploring protein interactors of disrupted-in-schizophrenia-1 (DISC1), a promising risk factor for schizophrenia and bipolar disorder, we already came across PCM1 as a potential protein interactor of DISC1. This interaction has been confirmed by yeast two-hybrid and biochemical methods. In immunofluorescent cell staining, a pool of DISC1 and PCM1 are co-stained at the centrosome. Therefore, this genetic study is really encouraging us to move beyond our preliminary study on DISC1 and PCM1.

Of interest, Gurling and colleagues reported in the paper that the cases with the PCM1 genetic susceptibility showed a significant relative reduction in the volume of orbitofrontal cortex gray matter in comparison with patients with non-PCM1-associated schizophrenia, who showed gray matter volume reduction in the temporal pole, hippocampus, and inferior temporal cortex. This may be in accordance with our previous publication (Sawamura et al., 2005) reporting the alteration in subcellular distribution of DISC1 in the orbitofrontal cortex of the patients with schizophrenia.

Although a possible link of DISC1 and PCM1 in the pathophysiology of schizophrenia is still hypothetical, the intriguing work by Dr. Gurling and colleagues may now open a window in studying the centrosomal “pathway” in association with schizophrenia. Epistatic interactions on DISC1, PCM1, and related molecules may also be of interest for future studies.

Regarding the possibility that PCM1 may have ties to DISC1, it's of interest that when PCM1 function is inhibited there is reduced targeting of centrin, pericentrin and ninein to the centrosome (1). Miyoshi and colleagues (2) report that their data indicate that DISC1 localizes to the centrosome by binding to kendrin/pericentrinB. Might there be a failure of DISC1 to localize in the centrosome in PCM1 deficiency?

Do these families with PCM1-associated schizophrenia also have a history of scleroderma? It is also of interest that PCM1 is an autoantigen target in scleroderma (3), and there is a report of cerebral involvement of scleroderma presenting as schizophrenia-like psychosis (4).

Abelson Helper Integration Site 1 (AHI1) gene is a candidate gene for schizophrenia and mutations in AHI1 underlie the autosomal recessive Joubert Syndrome in which cerebellar vermis hypoplasia is reported.(5) Increased cerebellar vermis white-matter volume has recently been reported in males with schizophrenia.(6)

It's interesting that mutations in the centrosomal protein...  Read more

Regarding the possibility that PCM1 may have ties to DISC1, it's of interest that when PCM1 function is inhibited there is reduced targeting of centrin, pericentrin and ninein to the centrosome (1). Miyoshi and colleagues (2) report that their data indicate that DISC1 localizes to the centrosome by binding to kendrin/pericentrinB. Might there be a failure of DISC1 to localize in the centrosome in PCM1 deficiency?

Do these families with PCM1-associated schizophrenia also have a history of scleroderma? It is also of interest that PCM1 is an autoantigen target in scleroderma (3), and there is a report of cerebral involvement of scleroderma presenting as schizophrenia-like psychosis (4).

Abelson Helper Integration Site 1 (AHI1) gene is a candidate gene for schizophrenia and mutations in AHI1 underlie the autosomal recessive Joubert Syndrome in which cerebellar vermis hypoplasia is reported.(5) Increased cerebellar vermis white-matter volume has recently been reported in males with schizophrenia.(6)

It's interesting that mutations in the centrosomal protein nephrocystin-6 may also cause Joubert syndrome and that it activates ATF4. (7) Morris and colleagues (8) find that DISC1 interacts with ATF4 - a schizophrenia locus on 22q13 and ATF5. Perhaps failure of DISC1 to localize to the centrosome due to PCMI deficiency may also result in reduced activation of ATF4/5.

In view of the study by Al Sarraj and colleagues (9) finding that ATF4/5 stimulate asparagine synthetase activity might we suspect that reduced activation of ATF4 and ATF5 in schizophrenia may explain the decreased CSF asparagine levels reported (10) Perhaps asparagine synthetase might be a suitable drug target in schizophrenia. Of further relevance is the processed pseudogene for asparagine synthetase found upstream of GNAL -18p11, a region linked to bipolar disorder and schizophrenia. (11) Hirotsune and colleagues (12) report that an expressed pseudogene regulates messenger-RNA stability of its homologous coding gene.

Might we also suspect a role for DISC1 in oligodendrocyte dysfunction in schizophrenia? Reduced myelination is reported in neonatal rats deprived of asparagine?(13) It would seem relevant however that Mason and colleagues (14) find that ATF5 regulates proliferation and differentiation of oligodendrocytes, with loss of function resulting in accelerated oligodendrocyte differentiation

References:

1. Dammermann A, Merdes A. Assembly of centrosomal proteins and microtubule organization depends on PCM-1. J Cell Biol. 2002 Oct 28;159(2):255-66. Epub 2002 Oct 28. Abstract

2. Miyoshi K, Asanuma M, Miyazaki I, Diaz-Corrales FJ, Katayama T, Tohyama M, Ogawa N. DISC1 localizes to the centrosome by binding to kendrin. Biochem Biophys Res Commun. 2004 May 14;317(4):1195-9. Abstract

3. Bao L, Zimmer WE, Balczon R. Autoepitope mapping of the centrosome autoantigen PCM-1 using scleroderma sera with anticentrosome autoantibodies. Autoimmunity. 1995;22(4):219-28. Abstract

4. Muller N, Gizycki-Nienhaus B, Botschev C, Meurer M. Cerebral involvement of scleroderma presenting as schizophrenia-like psychosis. Schizophr Res. 1993 Aug;10(2):179-81. Abstract (5) Eur J Hum Genet. 2006 Jun 14; [Epub ahead of print] AHI1, a pivotal neurodevelopmental gene, and C6orf217 are associated with susceptibility to schizophrenia. Amann-Zalcenstein D, Avidan N, Kanyas K, Ebstein RP, Kohn Y, Hamdan A, Ben-Asher E, Karni O, Mujaheed M, Segman RH, Maier W, Macciardi F, Beckmann JS, Lancet D, Lerer B. (6) J Psychiatr Res. 2006 Apr 18; [Epub ahead of print] Increased cerebellar vermis white-matter volume in men with schizophrenia. Lee KH, Farrow TF, Parks RW, Newton LD, Mir NU, Egleston PN, Brown WH, Wilkinson ID, Woodruff PW (7) Nat Genet. 2006 Jun;38(6):674-81. Epub 2006 May 7. The centrosomal protein nephrocystin-6 is mutated in Joubert syndrome and activates transcription factor ATF4. Sayer JA, Otto EA, O'Toole JF, Nurnberg G, Kennedy MA, Becker C, Hennies HC, Helou J, Attanasio M, Fausett BV, Utsch B, Khanna H, Liu Y, Drummond I, Kawakami I, Kusakabe T, Tsuda M, Ma L, Lee H, Larson RG, Allen SJ, Wilkinson CJ, Nigg EA,Shou C, Lillo C, Williams DS, Hoppe B, Kemper MJ, Neuhaus T, Parisi MA, Glass IA, Petry M, Kispert A, Gloy J, Ganner A, Walz G, Zhu X, Goldman D, Nurnberg P, Swaroop A, Leroux MR, Hildebrandt F. (8) Hum Mol Genet. 2003 Jul 1;12(13):1591-608. Links DISC1 (Disrupted-In-Schizophrenia 1) is a centrosome-associated protein that interacts with MAP1A, MIPT3, ATF4/5 and NUDEL: regulation and loss of interaction with mutation. Morris JA, Kandpal G, Ma L, Austin CP. (9) Biol Chem. 2005 Sep;386(9):873-9. Links Regulation of asparagine synthetase gene transcription by the basic region leucine zipper transcription factors ATF5 and CHOP. Al Sarraj J, Vinson C, Thiel G. (10) Nippon Rinsho. 1992 Jul;50(7):1643-9. Links [Amino acid metabolism in endogenous psychoses: significance of amino acids as neurotransmitter, precursor of monoamines and allosteric regulator of neuro-receptors] Doi N. (11) Mol Psychiatry. 2000 Sep;5(5):495-501. Links Sequence and genomic organization of the human G-protein Golfalpha gene (GNAL) on chromosome 18p11, a susceptibility region for bipolar disorder and schizophrenia. Vuoristo JT, Berrettini WH, Overhauser J, Prockop DJ, Ferraro TN, Ala-Kokko L. (12) Nature. 2003 May 1;423(6935):26-8. An expressed pseudogene regulates the messenger-RNA stability of its homologous coding gene. Hirotsune S, Yoshida N, Chen A, Garrett L, Sugiyama F, Takahashi S, Yagami K, Wynshaw-Boris A, Yoshiki A. (13) Dev Neurosci. 1982;5(4):332-44. Brain development in neonatal rats nursing asparagine-deprived dams. Newburg DS, Fillios LC. (14) Mol Cell Neurosci. 2005 Jul;29(3):372-80. ATF5 regulates the proliferation and differentiation of oligodendrocytes. Mason JL, Angelastro JM, Ignatova TN, Kukekov VG, Lin G, reene LA, Goldman JE.

Den Hollander and colleagues (1) report that mutations in CEP290-nephrocystin-6 are a frequent cause of Leber's Congenital Amaurosis (LCA). Autistic signs are reported in both Joubert syndrome and LCA (2,3). Perhaps asparagine may be useful for those with LCA and dysmyelination.

References:

1. den Hollander AI, Koenekoop RK, Yzer S, Lopez I, Arends ML, Voesenek KE, Zonneveld MN, Strom TM, Meitinger T, Brunner HG, Hoyng CB, van den Born LI, Rohrschneider K, Cremers FP. Mutations in the CEP290 (NPHP6) Gene Are a Frequent Cause of Leber Congenital Amaurosis. Am J Hum Genet. 2006 Sep;79(3):556-61. Epub 2006 Jul 11. Abstract

2. Curless RG, Flynn JT, Olsen KR, Post MJ. Leber congenital amaurosis in siblings with diffuse dysmyelination. Pediatr Neurol. 1991 May-Jun;7(3):223-5. Abstract

3. Rogers SJ, Newhart-Larson S. Characteristics of infantile autism in five children with Leber's congenital amaurosis. Dev Med Child Neurol. 1989 Oct;31(5):598-608. Abstract

View all comments by Mary Reid

The asparagine synthetase gene has been mapped to 7q21.3 (1). Childhood-onset schizophrenia/autistic disorder has been described in a child with a translocation breakpoint at 7q21. Of further interest is that alcohol/drug abuse, severe impulsivity, paranoid personality, and language delay have been reported in other family members carrying this translocation.

Maybe the increased risk of schizophrenia following famine may be explained by the fact that starvation induces expression of ATF4 and asparagine synthetase. Is there an increased risk of mutation in these genes as a long-term response to famine?

References:

1. Heng HH, Shi XM, Scherer SW, Andrulis IL, Tsui LC. Refined localization of the asparagine synthetase gene (ASNS) to chromosome 7, region q21.3, and characterization of the somatic cell hybrid line 4AF/106/KO15. Cytogenet Cell Genet. 1994;66(2):135-8. Abstract

2. Yan WL, Guan XY, Green ED, Nicolson R, Yap TK, Zhang J, Jacobsen LK, Krasnewich DM, Kumra S, Lenane MC, Gochman P, Damschroder-Williams PJ, Esterling LE, Long RT, Martin BM, Sidransky E, Rapoport JL, Ginns EI. Childhood-onset schizophrenia/autistic disorder and t(1;7) reciprocal translocation: identification of a BAC contig spanning the translocation breakpoint at 7q21. Am J Med Genet. 2000 Dec 4;96(6):749-53. Abstract

View all comments by Mary Reid