PPAN

PPAN
Identifiers
Aliases	PPAN, BXDC3, SSF, SSF-1, SSF1, SSF2, peter pan homolog (Drosophila), peter pan homolog
External IDs	OMIM: 607793; MGI: 2178445; HomoloGene: 5690; GeneCards: PPAN; OMA:PPAN - orthologs
Gene location (Human)
Chr.	Chromosome 19 (human)
End	10,112,012 bp
Gene location (Mouse)
Chr.	Chromosome 9 (mouse)
End	20,803,474 bp
RNA expression pattern
	Top expressed in
	sural nerve; ; granulocyte; ; mucosa of transverse colon; ; gonad; ; gastrocnemius muscle; ; parotid gland; ; skin of leg; ; skin of abdomen; ; left uterine tube; ; apex of heart;
	Top expressed in
	yolk sac; ; epiblast; ; bone marrow; ; embryo; ; zygote; ; embryo; ; secondary oocyte; ; primary oocyte; ; placenta; ; pancreas;
	More reference expression data
	n/a
Gene ontology
Molecular function	rRNA binding; RNA binding;
Cellular component	nucleolus; preribosome, large subunit precursor; nucleus;
Biological process	ribosomal large subunit assembly;
	Sources:Amigo / QuickGO
Orthologs
	56342
	235036
	ENSG00000130810
	ENSMUSG00000004100
	Q9NQ55
	Q91YU8
	NM_001346139; NM_001346141; NM_020230
	NM_145610
	NP_001035754; NP_001185619
	NP_663585
	Wikidata
View/Edit Human	View/Edit Mouse

Suppressor of SWI4 1 homolog is a protein that in humans is encoded by the PPAN gene.

The protein encoded by this gene is an evolutionarily conserved protein similar to yeast SSF1 as well as to the gene product of the Drosophila gene peter pan (PPAN). SSF1 is known to be involved in the second step of mRNA splicing. Both SSF1 and PPAN are essential for cell growth and proliferation. This gene was found to cotranscript with P2RY11/P2Y(11), an immediate downstream gene on the chromosome that encodes an ATP receptor. The chimeric transcripts of this gene and P2RY11 were found to be ubiquitously present and regulated during granulocytic differentiation. Exogenous expression of this gene was reported to reduce the anchorage-independent growth of some tumor cells.

Although being involved in ribosome biogenesis, human PPAN is not merely localized in nucleoli, but also in mitochondria. Depletion of PPAN provokes apoptosis as observed by increased amounts of p53 and its target gene p21, BAX-driven depolarisation of mitochondria, cytochrome c release as well as caspase-dependent cleavage of PARP. Recent studies revealed that PPAN participates in the regulation of mitochondrial homeostasis, presumably via modulation of autophagy. Furthermore, PPAN is required for proper cycling of cells since down regulation of PPAN in cancer cells results in a p53-independent cell cycle arrest.

One of the introns of PPAN encodes the Small nucleolar RNA SNORD105.