1. Summary protein-protein aPKC interactions flybase results

aPKC: atypical protein kinase C/ Serine/threonine protein kinase

• function: encodes a member of the conserved Par complex, is required for apico- basal cell polarity in the germ line as well as in epithelial and neural precursor cells, for epithelial planar cell polarity and for cell proliferation.

• expression pattern:

• indirect flight muscle ((thoracic dorso-longitudinal muscles (DLM))
• high in MNs (70% in leg muscle motor neurons)

Protein-protein interaction	source	MN expression level interaction partner/aPKC
aPKC, FBgn0261854	(Colosimo et al., 2010)	high
aPKC – Cdc42	Leibfried et al., 2013)	Intermediate-low
aPKC – Dap160	Chabu and Doe, 2008)	intermediate
aPKC – Magi	Padash Barmchi et al., 2016)	low
aPKC – Myo10A	Liu et al., 2008)	low
aPKC – Patj	Sotillos et al., 2004)	low
aPKC – Rap1	Carmena et al., 2011)	intermediate
aPKC – Tsp2A	Xu et al., 2019)	low
aPKC – Vhl	Duchi et al., 2010)	low
aPKC – aurA	Wirtz-Peitz et al., 2008)	low
aPKC – baz	Holly et al., 2020, Casas-Tintó and Ferrús, 2019, Padash Barmchi et al., 2016, Goh et al., 2013, Duchi et al., 2010, Morais-de-Sá et al., 2010, Simões et al., 2010, Kim et al., 2009, Krahn et al., 2009, Wirtz-Peitz et al., 2008, Wang and Riechmann, 2007, Djiane et al., 2005, Harris and Peifer, 2005, Betschinger et al., 2003, Wodarz et al., 2000	low
aPKC – clu	Goh et al., 2013)	Intermediate-low
aPKC – crb	Kempkens et al., 2006, Sotillos et al., 2004)	low
aPKC – dlg1	Golub et al., 2017)	high
aPKC – futsch	Ruiz-Canada et al., 2004)	high
aPKC – fz	Djiane et al., 2005)	intermediate
aPKC – kibra	Jin et al., 2015	low
aPKC – l(2)gl	(Portela et al., 2024, Calero-Cuenca et al., 2016, Goh et al., 2013, Guruharsha et al., 2011, Tian and Deng, 2008, Wirtz-Peitz et al., 2008, Betschinger et al., 2003	low
aPKC – mira	Atwood and Prehoda, 2009, Wirtz-Peitz et al., 2008)	low
aPKC – mts	Chabu and Doe, 2009, Ogawa et al., 2009)	intermediate
aPKC – nuf	Calero-Cuenca et al., 2016)	Intermediate-low
aPKC – numb	Wirtz-Peitz et al., 2008)	Intermediate-high
aPKC – par-1	(Calero-Cuenca et al., 2016, Tian and Deng, 2008)	high
aPKC – par-6	(Nunes de Almeida et al., 2019, Calero-Cuenca et al., 2016, Neumüller et al., 2012, Guruharsha et al., 2011, Atwood and Prehoda, 2009, Kim et al., 2009, Wirtz-Peitz et al., 2008, Djiane et al., 2005, Hutterer et al., 2004, Ruiz-Canada et al., 2004, Betschinger et al., 2003)	low
aPKC – pbl	(Rosa et al., 2015)	low
aPKC – pon	(Wirtz-Peitz et al., 2008)	low
aPKC – ref(2)P	(Avila et al., 2002)	low
aPKC – sdt	(Koch et al., 2016)	high
aPKC – sif	(Wang et al., 2018)	high
aPKC – tws	(Chabu and Doe, 2009)	intermediate
aPKC – wupA	(Casas-Tintó and Ferrús, 2019)	intermediate
aPKC – yrt	(Gamblin et al., 2014)	intermediate

1.1 Potential aPKC protein interaction partners in MNs

Gene name	Flybase ID	Protein	Description
discs large 1(dlg)	FBgn0001624	guanylate kinase	cell polarity maintenance of apicobasal polaritycellular growth control during larval developmentantagonistic to the aPKC complex in polarity regulation and synaptic development
futsch		microtubule binding protein	formation of synaptic buttons at the neuromuscular junctions
par-1	FBgn0260934	non-specific serine/threonine protein kinase	microtubule cytoskeleton organization,axis specification and cell polarity
stardust (sdt)	FBgn0261873	guanylate kinase	maintenance of apico-basal cell polarity organization of zonula adherens
still life (sif)	FBgn0085447	guanine nucleotide exchange factor for Rho family GTPases	regulation synaptic growth at NMJs
numb	FBgn0002973	membrane-associated inhibitor of Notch signaling	Inhibitor of notch signalingcontrols neuroblast and sense organ precursor asymmetric division

1.2 Summary RNA-protein interactions aPKC-flybase

RNA-protein interaction	Flybase ID	source	MN expression level interaction partner/aPKC
aPKC – kin17		(Connell et al., 2024)	low
aPKC – orb		(Barr et al., 2019)	intermediate
aPKC – orb2	FBgn0264307	(Xu et al., 2014, Mastushita-Sakai et al., 2010)	high

2. Promotor sequence analysis FoxP target genes

dFoxP

• function:  transcription factor expressed in the nervous system; involved in locomotion, operant self-learning and courtship behavior

• consensus seq FoxP: AAACAaATTTC (Santos et al., 2015; JASPAR data base)

• human ortholog:  Hsap\FOXP4, Hsap\FOXP1, Hsap\FOXP2, Hsap\FOXP3

• expression pattern:

• indirect flight muscle (thoracic dorso-longitudinal muscles (DLM))
• leg muscle motor neuron (high)

2.1 Potential FoxP target genes

AAACAAATTTC

insc – Inscuteable (insc)

• function: encodes an adaptor protein required for asymmetric cell division; interacts with the microtubule binding protein encoded by mud and the adaptor encoded by pins; also binds to the apical complex proteins encoded by baz, par-6 and aPKC and may recruit microtubule binding proteins to the apical cell cortex to induce apical-basal spindle orientation

•  human ortholog:  –

• expression in MNs: low

AAACACATTTC

CG15233 

• function: uncharacterized protein; putative target of stat and escargo, two master regulators of intestinal stem cells (Khanbabaei et al., 2023)

• human ortholog:  –

• expression pattern:
• indirect flight muscle
• low in MNs (leg muscle motor neuron)

bowl 

• function: putative transcription factor; leg joint formation, acting downstream of notch to pattern the leg tarsal segments;

• acts downstream of drm and lin during foregut and hindgut patterning and morphogenesis; involved in cell rearrangement during elongation of the embryonic hindgut; regulates expression of hindgut patterning genes to establish the small intestine region of the embryonic hindgut

• human orthologs: Hsap\EGR2, Hsap\KLF11, Hsap\EGR4, Hsap\ZBTB4, Hsap\KLF15, Hsap\EGR1, Hsap\OSR2, Hsap\OSR1, Hsap\ZBTB38, Hsap\ZBTB2, Hsap\EGR3, Hsap\SP2, EGR: early growth response genes, supress exessive immune responses dysfunctions associated with inflammatory autoimmunse diseases like multiple sclerosis (MS), type 1 diabetes and inflammatory bowel disease (Powrie and Coffman 1993; Liblau, Singer et al. 1995, Morita et al., 2016)

• expression pattern:
• indirect flight muscle
• low in MNs (leg muscle motor neuron)

AAACATATTTC

CG4477 

• function: peptidase S1 domain-containing protein; Serine-type endopeptidase   activity, involved in wing disc dorsal/ventral pattern formation; proteolysis,

• human ortholog: responsible for vital processes in man such as digestion, blood coagulation, fibrinolysis, development, fertilization, apoptosis and immunity

• expression pattern:
• low in MNs (leg muscle motor neuron)
• moderate expression in muscle cells  (indirect flight muscle )

CG30354- UQCR-11L

• function: cytochrome b-c1 complex subunit 6; component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex) which is part of the mitochondrial respiratory chain; formation of the complex between cytochromes c and c1. UQCRH/QCR6 family. [a.k.a. FBgn0050354, UQCR-11L-PB, UQCR-11L-PA, CG30354],

• human ortholog: Hsap\UQCRH (Ubiquinol-Cytochrome C Reductase Hinge) protein

• expression pattern:
• indirect flight muscle
• low in MNs (leg muscle motor neuron)

AAACAGATTTC

CG10864 

• function: potassium ion leak channel activity; potassium channel activity; involved in potassium ion transmembrane transport; stabilization of membrane potential; two pore domain potassium channel (TC 1.A.1.8) family

• human orthologs: Hsap\KCNK4, Hsap\KCNK18, Hsap\KCNK5, Hsap\KCNK7, Hsap\KCNK2, Hsap\KCNK10, Hsap\KCNK12, Hsap\KCNK16, Hsap\KCNK17, Hsap\KCNK6, Hsap\KCNK1

• expression pattern:
• indirect flight muscle
• low in MNs (leg muscle motor neuron)

AAACAATTTC

Lhr – Lethal hybrid rescue (Lhr)

• function: encodes a protein required to repress transposable element and satellite DNA expression. It also has a gain-of-function phenotype of causing lethality in F1 male hybrids between D. melanogaster and D. simulans

• human orthologs: –

• expression pattern:
• indirect flight muscle
• low in MNs (leg muscle motor neuron)

Source: EPD The Eukaryotic Promoter Database